scholarly journals Receptors and Lethal Effect of Bacillus thuringiensis Insecticidal Crystal Proteins to the Anticarsia gemmatalis (Lepidoptera, Noctuidae)

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Lidia Mariana Fiuza ◽  
Neiva Knaak ◽  
Rogério Fernando Pires da Silva ◽  
João Antônio Pêgas Henriques
Keyword(s):  
Bacillus Thuringiensis ◽  
Lethal Effect ◽  
Anticarsia Gemmatalis ◽  
Binding Studies ◽  
Crystal Proteins ◽  
Binding Data ◽  
Lepidoptera Noctuidae ◽  
Insecticidal Crystal Proteins

Bioassays with insecticidal crystal proteins (ICPs) from Bacillus thuringiensis have demonstrated that Cry1Aa, Cry1Ac, and Cry1Ba are the most active toxins on larvae of the Anticarsia gemmatalis. The toxins Cry1Da and Cry1Ea are less toxic, and toxins Cry2Aa are not active. Binding of these ICPs to midgut sections of the A. gemmatalis larvae was studied using streptavidin-mediated detection. The observed staining patterns showed that Cry1Aa and Cry1Ac bound to the brush border throughout the whole length of the midgut. However, the binding sites of Cry1Ba were not evenly distributed in the midgut microvilli. The in vivo assays against larvae of 2nd instar A. gemmatalis confirmed the results from the in vitro binding studies. These binding data correspond well with the bioassay results, demonstrating a correlation between receptors binding and toxicity of the tested ICPs in this insect.

Larvicidal toxins fromBacillusthuringiensissubspp.kurstaki,morrisoni(straintenebrionis), andisraelensishave no microbicidal or microbiostatic activity against selected bacteria, fungi, and algae in vitro

2002 ◽  
Vol 48 (3) ◽  
pp. 262-267 ◽  
Author(s):  
J Koskella ◽  
G Stotzky
Keyword(s):  
Bacillus Thuringiensis ◽  
Mixed Culture ◽  
Gram Positive ◽  
Gram Negative ◽  
Crystal Proteins ◽  
Growth Of A Variety ◽  
Insecticidal Toxins ◽  
Antibiotic Effect ◽  
Insecticidal Crystal Proteins

The insecticidal toxins from Bacillus thuringiensis subspp. kurstaki (antilepidopteran), morrisoni strain tenebrionis (anticoleopteran), and israelensis (antidipteran) did not affect the growth of a variety of bacteria (8 gram-negative, 5 gram-positive, and a cyanobacterium), fungi (2 Zygomycetes, 1 Ascomycete, 2 Deuteromycetes, and 2 yeasts), and algae (primarily green and diatoms) in pure and mixed culture, as determined by dilution, disk-diffusion, and sporulation assays with purified free and clay-bound toxins. The insecticidal crystal proteins from B. thuringiensis subspp. kurstaki and israelensis had no antibiotic effect on various gram-positive bacteria.Key words: insecticidal toxins, Bacillus thuringiensis, microbiostatic, microbicidal.

scholarly journals Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae)

2010 ◽  
Vol 70 (3) ◽  
pp. 677-684 ◽  
Author(s):  
N. Knaak ◽  
AR. Franz ◽  
GF. Santos ◽  
LM. Fiuza
Keyword(s):  
Bacillus Thuringiensis ◽  
Spodoptera Frugiperda ◽  
Oryza Sativa L ◽  
Histopathological Analysis ◽  
Initial Growth ◽  
Bacterial Strains ◽  
Cry Protein ◽  
Lepidoptera Noctuidae

Among the phytophagous insects which attack crops, the fall armyworm, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera, Noctuidae) is particularly harmful in the initial growth phase of rice plants. As a potential means of controlling this pest, and considering that the entomopathogen Bacillus thuringiensis Berliner demonstrates toxicity due to synthesis of the Cry protein, the present study was undertaken to evaluate this toxic effect of B. thuringiensis thuringiensis 407 (pH 408) and B. thuringiensis kurstaki HD-73 on S. frugiperda. The following method was used. Both bacterial strains were evaluated in vitro in 1st instar S. frugiperda caterpillars, by means of histopathological assays. The Cry1Ab and Cry1Ac proteins, codified by the respective strains of B. thuringiensis, were evaluated in vivo by bioassays of 1st instar S. frugiperda caterpillars in order to determine the Mean Lethal Concentration (LC50). The results of the histopathological analysis of the midget of S. frugiperda caterpillars demonstrate that treatment with the B. thuringiensis thuringiensis strain was more efficient, because the degradations of the microvilosities started 9 hours after treatment application (HAT), while in the B. thuringiensis kurstaki the same effect was noticed only after 12 HAT. Toxicity data of the Cry1Ab and Cry1Ac proteins presented for the target-species LC50 levels of 9.29 and 1.79 μg.cm-2 respectively. The strains and proteins synthesised by B. thuringiensis thuringiensis and B. thuringiensis kurstaki are effective in controlling S. frugiperda, and may be used to produce new biopesticides or the genes may be utilised in the genetic transformation of Oryza sativa L.

scholarly journals ADR1-Mediated Transcriptional Activation Requires the Presence of an Intact TFIID Complex

1998 ◽  
Vol 18 (10) ◽  
pp. 5861-5867 ◽  
Author(s):  
Philip B. Komarnitsky ◽  
Edward R. Klebanow ◽  
P. Anthony Weil ◽  
Clyde L. Denis
Keyword(s):  
Transcriptional Activation ◽  
Yeast Cells ◽  
Binding Studies ◽  
Whole Cell ◽  
Transactivation Domains ◽  
Cell Extracts ◽  
Genes Expression ◽  
Tfiid Complex

ABSTRACT The yeast transcriptional activator ADR1, which is required forADH2 and other genes’ expression, contains four transactivation domains (TADs). While previous studies have shown that these TADs act through GCN5 and ADA2, and presumably TFIIB, other factors are likely to be involved in ADR1 function. In this study, we addressed the question of whether TFIID is also required for ADR1 action. In vitro binding studies indicated that TADI of ADR1 was able to retain TAFII90 from yeast extracts and TADII could retain TBP and TAFII130/145. TADIV, however, was capable of retaining multiple TAFIIs, suggesting that TADIV was binding TFIID from yeast whole-cell extracts. The ability of TADIV truncation derivatives to interact with TFIID correlated with their transcription activation potential in vivo. In addition, the ability of LexA-ADR1-TADIV to activate transcription in vivo was compromised by a mutation in TAFII130/145. ADR1 was found to associate in vivo with TFIID in that immunoprecipitation of either TAFII90 or TBP from yeast whole-cell extracts specifically coimmunoprecipitated ADR1. Most importantly, depletion of TAFII90 from yeast cells dramatically reducedADH2 derepression. These results indicate that ADR1 physically associates with TFIID and that its ability to activate transcription requires an intact TFIID complex.

scholarly journals Formation of a Complex between Nucleolin and Replication Protein a after Cell Stress Prevents Initiation of DNA Replication

2000 ◽  
Vol 149 (4) ◽  
pp. 799-810 ◽  
Author(s):  
Yaron Daniely ◽  
James A. Borowiec
Keyword(s):  
Dna Replication ◽  
Ribosome Biogenesis ◽  
Protein A ◽  
Simian Virus 40 ◽  
Replication Protein A ◽  
Cell Stress ◽  
Replication Protein ◽  
Binding Studies

We used a biochemical screen to identify nucleolin, a key factor in ribosome biogenesis, as a high-affinity binding partner for the heterotrimeric human replication protein A (hRPA). Binding studies in vitro demonstrated that the two proteins physically interact, with nucleolin using an unusual contact with the small hRPA subunit. Nucleolin significantly inhibited both simian virus 40 (SV-40) origin unwinding and SV-40 DNA replication in vitro, likely by nucleolin preventing hRPA from productive interaction with the SV-40 initiation complex. In vivo, use of epifluorescence and confocal microscopy showed that heat shock caused a dramatic redistribution of nucleolin from the nucleolus to the nucleoplasm. Nucleolin relocalization was concomitant with a tenfold increase in nucleolin–hRPA complex formation. The relocalized nucleolin significantly overlapped with the position of hRPA, but only poorly with sites of ongoing DNA synthesis. We suggest that the induced nucleolin–hRPA interaction signifies a novel mechanism that represses chromosomal replication after cell stress.

scholarly journals Pyrazinamide triggers degradation of its target aspartate decarboxylase

2019 ◽  
Author(s):  
Pooja Gopal ◽  
Jickky Sarathy ◽  
Michelle Yee ◽  
Priya Ragunathan ◽  
Joon Shin ◽  
...  
Keyword(s):  
Protein Function ◽  
Enzyme Inhibitor ◽  
Drug Regimen ◽  
Growth Media ◽  
Antibacterial Drug ◽  
Missense Mutations ◽  
Binding Studies ◽  
Drug Induced

AbstractThe introduction of pyrazinamide (PZA) in the tuberculosis drug regimen shortened treatment from 12 to 6 months 1. PZA is a prodrug that is activated by a Mycobacterium tuberculosis (Mtb) amidase to release its bioactive component pyrazinoic acid (POA) 2. Aspartate decarboxylase PanD, a proenzyme activated by autocatalytic cleavage (Supplementary Fig. 1A, 3) and required for Coenzyme A (CoA) biosynthesis, emerged as a target of POA 4-7. In vitro and in vivo screening to isolate spontaneous POA-resistant Mtb mutants identified missense mutations in either panD or the unfoldase clpC1, encoding a component of the caseinolytic protease ClpC1-ClpP 4,6-9. Overexpression and binding studies of PanD or ClpC1 pointed to PanD as the direct target of POA whereas clpC1 mutations appeared to indirectly cause resistance 4,5,7,9,10. Indeed, supplementing growth media with CoA precursors downstream of the PanD catalyzed step conferred POA resistance 4,7,11. Metabolomic analyses and biophysical studies using recombinant proteins confirmed targeting of PanD by POA 5. However, the exact molecular mechanism of PanD inhibition by POA remained unknown. While most drugs act by inhibiting protein function upon target binding, we show here that POA is not a bona fide enzyme inhibitor. Rather, POA binding to PanD triggers degradation of the protein by ClpC1-ClpP. Thus, the old tuberculosis drug PZA promotes degradation of its target. While novel for an antibacterial, drug-induced target degradation has recently emerged as a strategy in drug discovery across disease indications. Our findings provide the basis for the rational discovery of next generation PZA.

Membrane binding of insecticidal crystal proteins of Bacillus thuringiensis

2000 ◽  
Vol 28 (5) ◽  
pp. A438-A438
Author(s):  
Hiroshi Sakai ◽  
Tohru Komano ◽  
Masashi Yamagiwa
Keyword(s):  
Bacillus Thuringiensis ◽  
Membrane Binding ◽  
Crystal Proteins ◽  
Insecticidal Crystal Proteins
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