scholarly journals What is the role of zooxanthellae during coral bleaching? Review of zooxanthellae and their response to environmental stress

2021 ◽  
Vol 117 (7/8) ◽  
Author(s):  
Anuschka Curran ◽  
Sandra Barnard
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Coral Reefs ◽  
Environmental Stress ◽  
Coral Bleaching ◽  
Stress Responses ◽  
Coral Tissue ◽  
Ecological Traits ◽  
Shock Proteins ◽  
The Impact

Coral reefs are diverse and productive but sensitive ecosystems. Due to the impact of climate change, these organisms are in danger of dying out, mainly through the process of coral bleaching, which is the process by which zooxanthellae (algal endosymbionts) are expelled from their respective coral hosts, causing the coral to lose colour and become white. Coral bleaching has been linked to increases in sea surface temperatures as well as an increase in light intensity. We reviewed the different zooxanthellae taxa and their ecological traits, as well as the information available on the protective mechanisms present in zooxanthellae cells when they experience environmental stress conditions, such as temperature fluctuations, specifically concentrating on heat shock proteins and their response to antioxidant stress. The eight clades (A–H) previously recognised were reorganised into seven existing genera. Different zooxanthellae taxa exhibit different ecological traits such as their photosynthetic stress responses to light and temperature. Zooxanthellae have the ability to regulate the number and type of heat shock proteins (Hsps) they produce during a heat response. They can also regulate the host’s respective Hsps. Antioxidant responses that can prevent coral hosts from expelling the zooxanthellae, can be found both within exposed coral tissue and the zooxanthellae cells. Despite the lower likelihood of bleaching in South African coral reefs, genetic engineering presents a useful tool to understand and adapt traits within zooxanthellae genotypes to help mitigate coral bleaching in the future.

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
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Stress Responses ◽  
Thermal Tolerance ◽  
Molecular Mechanisms ◽  
Fluorescent Protein ◽  
Bacterial Cells ◽  
Induced Expression ◽  
Green Fluorescent ◽  
Shock Proteins

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.

Heat shock and stress response of Taenia solium and T. crassiceps (Cestoda)

Parasitology ◽  
2001 ◽  
Vol 122 (5) ◽  
pp. 583-588 ◽  
Author(s):  
L. VARGAS-PARADA ◽  
C. F. SOLÍS ◽  
J. P. LACLETTE
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Stress Responses ◽  
Stress Proteins ◽  
Taenia Solium ◽  
Western Blots ◽  
Prolonged Incubation ◽  
Larval Stages ◽  
Shock Proteins

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.

scholarly journals Cold and Heat Stress Diversely Alters Both Cauliflower Respiration and Distinct Mitochondrial Proteins Including OXPHOS Components and Matrix Enzymes

2018 ◽  
Author(s):  
Michał Rurek ◽  
Magdalena Czołpińska ◽  
Tomasz Andrzej Pawłowski ◽  
Włodzimierz Krzesiński ◽  
Tomasz Spiżewski
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Stress Responses ◽  
Protein Import ◽  
Plant Mitochondria ◽  
Complex Model ◽  
Mitochondrial Proteome ◽  
Metabolism Enzymes ◽  
Shock Proteins

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.

scholarly journals Are the Effects of Heat on Physiology Due to Heat Shock Proteins?

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 691c-691
Author(s):  
Robert E. Paull ◽  
Chris B. Watkins
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Stress Responses ◽  
Critical Role ◽  
Chilling Injury ◽  
Heat Treatments ◽  
Adaptation To Heat ◽  
Heat Shock Responses ◽  
Shock Proteins

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.

scholarly journals Small heat shock proteins target mutant cystic fibrosis transmembrane conductance regulator for degradation via a small ubiquitin-like modifier–dependent pathway

2013 ◽  
Vol 24 (2) ◽  
pp. 74-84 ◽  
Author(s):  
Annette Ahner ◽  
Xiaoyan Gong ◽  
Bela Z. Schmidt ◽  
Kathryn W. Peters ◽  
Wael M. Rabeh ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Airway Epithelial Cells ◽  
Small Heat Shock Proteins ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Shock Proteins ◽  
The Impact ◽  
Cystic Fibrosis Transmembrane

Small heat shock proteins (sHsps) bind destabilized proteins during cell stress and disease, but their physiological functions are less clear. We evaluated the impact of Hsp27, an sHsp expressed in airway epithelial cells, on the common protein misfolding mutant that is responsible for most cystic fibrosis. F508del cystic fibrosis transmembrane conductance regulator (CFTR), a well-studied protein that is subject to cytosolic quality control, selectively associated with Hsp27, whose overexpression preferentially targeted mutant CFTR to proteasomal degradation. Hsp27 interacted physically with Ubc9, the small ubiquitin-like modifier (SUMO) E2 conjugating enzyme, implying that F508del SUMOylation leads to its sHsp-mediated degradation. Enhancing or disabling the SUMO pathway increased or blocked Hsp27’s ability to degrade mutant CFTR. Hsp27 promoted selective SUMOylation of F508del NBD1 in vitro and of full-length F508del CFTR in vivo, which preferred endogenous SUMO-2/3 paralogues that form poly-chains. The SUMO-targeted ubiquitin ligase (STUbL) RNF4 recognizes poly-SUMO chains to facilitate nuclear protein degradation. RNF4 overexpression elicited F508del degradation, whereas Hsp27 knockdown blocked RNF4’s impact on mutant CFTR. Similarly, the ability of Hsp27 to degrade F508del CFTR was lost during overexpression of dominant-negative RNF4. These findings link sHsp-mediated F508del CFTR degradation to its SUMOylation and to STUbL-mediated targeting to the ubiquitin–proteasome system and thereby implicate this pathway in the disposal of an integral membrane protein.

scholarly journals Influence of Heating and Cyclic Tension on the Induction of Heat Shock Proteins and Bone-Related Proteins by MC3T3-E1 Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Eunna Chung ◽  
Alana Cherrell Sampson ◽  
Marissa Nichole Rylander
Keyword(s):  
Thermal Stress ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Tensile Stress ◽  
Bone Cells ◽  
Cyclic Strain ◽  
Fold Increase ◽  
Shock Proteins ◽  
Related Proteins ◽  
The Impact

Stress conditioning (e.g., thermal, shear, and tensile stress) of bone cells has been shown to enhance healing. However, prior studies have not investigated whether combined stress could synergistically promote bone regeneration. This study explored the impact of combined thermal and tensile stress on the induction of heat shock proteins (HSPs) and bone-related proteins by a murine preosteoblast cell line (MC3T3-E1). Cells were exposed to thermal stress using a water bath (44°C for 4 or 8 minutes) with postheating incubation (37°C for 4 hours) followed by exposure to cyclic strain (equibiaxial 3%, 0.2 Hz, cycle of 10-second tensile stress followed by 10-second rest). Combined thermal stress and tensile stress induced mRNA expression of HSP27 (1.41 relative fold induction (RFI) compared to sham-treated control), HSP70 (5.55 RFI), and osteopontin (1.44 RFI) but suppressed matrix metalloproteinase-9 (0.6 RFI) compared to the control. Combined thermal and tensile stress increased vascular endothelial growth factor (VEGF) secretion into the culture supernatant (1.54-fold increase compared to the control). Therefore, combined thermal and mechanical stress preconditioning can enhance HSP induction and influence protein expression important for bone tissue healing.

scholarly journals Cross-Omics Comparison of Stress Responses in Mesothelial Cells Exposed to Heat- versus Filter-Sterilized Peritoneal Dialysis Fluids

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Klaus Kratochwill ◽  
Thorsten O. Bender ◽  
Anton M. Lichtenauer ◽  
Rebecca Herzog ◽  
Silvia Tarantino ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Protein Expression ◽  
Stress Responses ◽  
Expression Profiles ◽  
Mrna Level ◽  
Mesothelial Cells ◽  
Peritoneal Mesothelial Cells ◽  
Shock Proteins

Recent research suggests that cytoprotective responses, such as expression of heat-shock proteins, might be inadequately induced in mesothelial cells by heat-sterilized peritoneal dialysis (PD) fluids. This study compares transcriptome data and multiple protein expression profiles for providing new insight into regulatory mechanisms. Two-dimensional difference gel electrophoresis (2D-DIGE) based proteomics and topic defined gene expression microarray-based transcriptomics techniques were used to evaluate stress responses in human omental peritoneal mesothelial cells in response to heat- or filter-sterilized PD fluids. Data from selected heat-shock proteins were validated by 2D western-blot analysis. Comparison of proteomics and transcriptomics data discriminated differentially regulated protein abundance into groups depending on correlating or noncorrelating transcripts. Inadequate abundance of several heat-shock proteins following exposure to heat-sterilized PD fluids is not reflected on the mRNA level indicating interference beyond transcriptional regulation. For the first time, this study describes evidence for posttranscriptional inadequacy of heat-shock protein expression by heat-sterilized PD fluids as a novel cytotoxic property. Cross-omics technologies introduce a novel way of understanding PDF bioincompatibility and searching for new interventions to reestablish adequate cytoprotective responses.

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