Role of receptor interaction in the mode of action of insecticidal Cry and Cyt toxins produced by Bacillus thuringiensis

Peptides ◽  
2007 ◽  
Vol 28 (1) ◽  
pp. 169-173 ◽  
Author(s):  
I. Gómez ◽  
L. Pardo-López ◽  
C. Muñoz-Garay ◽  
L.E. Fernandez ◽  
C. Pérez ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Mode Of Action ◽  
Receptor Interaction

Different Abilities of Thrombin Receptor Activating Peptide and Thrombin to Induce Platelet Calcium Rise and Full Release Reaction

1995 ◽  
Vol 74 (05) ◽  
pp. 1323-1328 ◽  
Author(s):  
Dominique Lasne ◽  
José Donato ◽  
Hervé Falet ◽  
Francine Rendu
Keyword(s):  
Essential Role ◽  
Calcium Influx ◽  
Dense Granule ◽  
Receptor Interaction ◽  
Thrombin Receptor ◽  
Release Reaction ◽  
External Calcium ◽  
Maximum Rise ◽  
Granule Release

SummarySynthetic peptides (TRAP or Thrombin Receptor Activating Peptide) corresponding to at least the first five aminoacids of the new N-terminal tail generated after thrombin proteolysis of its receptor are effective to mimic thrombin. We have studied two different TRAPs (SFLLR, and SFLLRN) in their effectiveness to induce the different platelet responses in comparison with thrombin. Using Indo-1/AM- labelled platelets, the maximum rise in cytoplasmic ionized calcium was lower with TRAPs than with thrombin. At threshold concentrations allowing maximal aggregation (50 μM SFLLR, 5 μM SFLLRN and 1 nM thrombin) the TRAPs-induced release reaction was about the same level as with thrombin, except when external calcium was removed by addition of 1 mM EDTA. In these conditions, the dense granule release induced by TRAPs was reduced by over 60%, that of lysosome release by 75%, compared to only 15% of reduction in the presence of thrombin. Thus calcium influx was more important for TRAPs-induced release than for thrombin-induced release. At strong concentrations giving maximal aggregation and release in the absence of secondary mediators (by pretreatment with ADP scavengers plus aspirin), SFLLRN mobilized less calcium, with a fast return towards the basal level and induced smaller lysosome release than did thrombin. The results further demonstrate the essential role of external calcium in triggering sustained and full platelet responses, and emphasize the major difference between TRAP and thrombin in mobilizing [Ca2+]j. Thus, apart from the proteolysis of the seven transmembrane receptor, another thrombin binding site or thrombin receptor interaction is required to obtain full and complete responses.

scholarly journals The Gene Regulatory Roles of Herbal Extracts on the Growth, Immune System, and Reproduction of Fish

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2167
Author(s):  
Ehsan Ahmadifar ◽  
Hamideh Pourmohammadi Fallah ◽  
Morteza Yousefi ◽  
Mahmoud A. O. Dawood ◽  
Seyed Hossein Hoseinifar ◽  
...  
Keyword(s):  
Immune System ◽  
Mode Of Action ◽  
Medicinal Herbs ◽  
Environmental Stressors ◽  
Fish Diet ◽  
Sustainable Aquaculture ◽  
Herbal Supplements ◽  
Aquatic Animals ◽  
Gene Regulatory

The crucial need for safe and healthy aquatic animals obligates researchers in aquaculture to investigate alternative and beneficial additives. Medicinal herbals and their extracts are compromised with diverse effects on the performances of aquatic animals. These compounds can affect growth performance and stimulate the immune system when used in fish diet. In addition, the use of medicinal herbs and their extracts can reduce oxidative stress induced by several stressors during fish culture. Correspondingly, aquatic animals could gain increased resistance against infectious pathogens and environmental stressors. Nevertheless, the exact mode of action where these additives can affect aquatic animals’ performances is still not well documented. Understanding the mechanistic role of herbal supplements and their derivatives is a vital tool to develop further the strategies and application of these additives for feasible and sustainable aquaculture. Gene-related studies have clarified the detailed information on the herbal supplements’ mode of action when administered orally in aquafeed. Several review articles have presented the potential roles of medicinal herbs on the performances of aquatic animals. However, this review article discusses the outputs of studies conducted on aquatic animals fed dietary, medicinal herbs, focusing on the gene expression related to growth and immune performances. Furthermore, a particular focus is directed to the expected influence of herbal supplements on the reproduction of aquatic animals.

scholarly journals Unraveling the role of polycystin-2/inositol 1,4,5-trisphosphate receptor interaction in Ca2+signaling

2010 ◽  
Vol 3 (6) ◽  
pp. 530-532 ◽  
Author(s):  
Eva Sammels ◽  
Benoit Devogelaere ◽  
Djalila Mekahli ◽  
Geert Bultyncki ◽  
Ludwig Missiaen ◽  
...  
Keyword(s):  
Receptor Interaction ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor

The role of Caenorhabditis elegans insulin‐like signaling in the behavioral avoidance of pathogenic Bacillus thuringiensis

2007 ◽  
Vol 21 (8) ◽  
pp. 1801-1812 ◽  
Author(s):  
Martin Hasshoff ◽  
Claudia Höhnisch ◽  
Daniela Tonn ◽  
Barbara Hasert ◽  
Hinrich Schulenburg
Keyword(s):  
Caenorhabditis Elegans ◽  
Bacillus Thuringiensis ◽  
Behavioral Avoidance

scholarly journals Heterologous desensitization of the cyclic AMP-independent glycogenolytic response in rat liver cells

1981 ◽  
Vol 200 (3) ◽  
pp. 509-514 ◽  
Author(s):  
B Bréant ◽  
S Keppens ◽  
H De Wulf
Keyword(s):  
Cyclic Amp ◽  
Glycogen Phosphorylase ◽  
Liver Glycogen ◽  
Receptor Interaction ◽  
Alpha Adrenergic Receptors ◽  
Rat Liver Cells ◽  
Heterologous Desensitization ◽  
Highly Correlated ◽  
Alpha Agonist

Vasopressin and alpha-adrenergic agonists are known to be potent cyclic AMP-independent Ca2+-dependent activators of liver glycogen phosphorylase. When hepatocytes are pre-incubated with increasing concentrations of vasopressin or of the alpha-agonist phenylephrine, they become progressively unresponsive to a second addition of the respective agonist. The relative abilities of six vasopressin analogues and of five alpha-agonists to activate glycogen phosphorylase and to cause subsequent desensitization are highly correlated, indicating that the same vasopressin and alpha-adrenergic receptors are involved in both responses. About 5-times-higher peptide concentrations are needed to desensitize the cells than to activate their glycogen phosphorylase, whereas the concentrations of alpha-agonists required for the desensitization are only twice those needed for the activation of phosphorylase. The desensitization is not mediated by a perturbation in the agonist-receptor interaction. It is clearly heterologous, i.e. it is not agonist-specific, and must therefore involve a mechanism common to both series of agonists. The evidence for a role of Ca2+ movements or phosphatidylinositol turnover is briefly discussed.

scholarly journals Analysis of the molecular basis of insecticidal specificity of Bacillus thuringiensis crystal δ-endotoxin

1987 ◽  
Vol 248 (1) ◽  
pp. 197-201 ◽  
Author(s):  
M Z Haider ◽  
D J Ellar
Keyword(s):  
Bacillus Thuringiensis ◽  
Membrane Proteins ◽  
Insect Cell ◽  
Receptor Interaction ◽  
Dual Specificity ◽  
Delta Endotoxin ◽  
Cell Membrane Proteins ◽  
Toxin Receptor ◽  
Osmotic Lysis ◽  
Initial Interaction

The mechanism of action and receptor binding of a dual-specificity Bacillus thuringiensis var. aizawai ICl delta-endotoxin was studied using insect cell culture. The native protoxin was labelled with 125I, proteolytically activated and the affinity of the resulting preparations for insect cell-membrane proteins was studied by blotting. The active preparations obtained by various treatments had characteristic specificity associated with unique polypeptides, and showed affinity for different membrane proteins. The lepidopteran-specific preparation (trypsin-treated protoxin containing 58 and 55 kDa polypeptides) bound to two membrane proteins in the lepidopteran cells but none in the dipteran cells. The dipteran-specific preparation (protoxin treated sequentially with trypsin and Aedes aegypti gut proteases, containing a 53 kDa polypeptide) bound to a 90 kDa membrane protein in the dipteran (A. aegypti) cells but bound to none in the lepidopteran cells or Drosophila melanogaster cells. The toxicity of trypsin-activated delta-endotoxin was completely inhibited by preincubation with D-glucose, suggesting a role for this carbohydrate in toxin-receptor interaction. The toxicity was also decreased by osmotic protectants to an extent proportional to their viscometric radius. These results support a proposal that initial interaction of toxin with a unique receptor determines the specificity of the toxin, following which cell death occurs by a mechanism of colloid osmotic lysis.

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