Evidence of a shared binding site for Bacillus thuringiensis Cry1Ac and Cry2Aa toxins in Cnaphalocrocis medinalis cadherin

2021 ◽  
Author(s):  
J. Zhong ◽  
S. Fang ◽  
M. Gao ◽  
L. Lu ◽  
X. Zhang ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Binding Site ◽  
Cnaphalocrocis Medinalis

scholarly journals Alanine Scanning Analyses of the Three Major Loops in Domain II of Bacillus thuringiensis Mosquitocidal Toxin Cry4Aa

2009 ◽  
Vol 76 (3) ◽  
pp. 860-865 ◽  
Author(s):  
Mohammad Tofazzal Hossain Howlader ◽  
Yasuhiro Kagawa ◽  
Ai Miyakawa ◽  
Ayaka Yamamoto ◽  
Tetsuya Taniguchi ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Binding Site ◽  
Receptor Binding ◽  
Significant Loss ◽  
Target Tissue ◽  
Receptor Binding Site ◽  
Multiple Binding Sites ◽  
Mosquitocidal Activity ◽  
Multiple Binding ◽  
Loop 2

ABSTRACT Cry4Aa produced by Bacillus thuringiensis is a dipteran-specific toxin and is of great interest for developing a bioinsecticide to control mosquitoes. Therefore, it is very important to characterize the functional motif of Cry4Aa that is responsible for its mosquitocidal activity. In this study, to characterize a potential receptor binding site, namely, loops 1, 2, and 3 in domain II, we constructed a series of Cry4Aa mutants in which a residue in these three loops was replaced with alanine. A bioassay using Culex pipiens larvae revealed that replacement of some residues affected the mosquitocidal activity of Cry4Aa, but the effect was limited. This finding was partially inconsistent with previous results which suggested that replacement of the Cry4Aa loop 2 results in a significant loss of mosquitocidal activity. Therefore, we constructed additional mutants in which multiple (five or six) residues in loop 2 were replaced with alanine. Although the replacement of multiple residues also resulted in some decrease in mosquitocidal activity, the mutants still showed relatively high activity. Since the insecticidal spectrum of Cry4Aa is specific, Cry4Aa must have a specific receptor on the surface of the target tissue, and loss of binding to the receptor should result in a complete loss of mosquitocidal activity. Our results suggested that, unlike the receptor binding site of the well-characterized molecule Cry1, the receptor binding site of Cry4Aa is different from loops 1, 2, and 3 or that there are multiple binding sites that work cooperatively for receptor binding.

Baseline Susceptibility of Cnaphalocrocis medinalis (Lepidoptera: Pyralidae) to Bacillus thuringiensis Toxins in China

2008 ◽  
Vol 101 (5) ◽  
pp. 1691-1696 ◽  
Author(s):  
L. Z. Han ◽  
P. L. Liu ◽  
M. L. Hou ◽  
Y. F. Peng
Keyword(s):  
Bacillus Thuringiensis ◽  
Cnaphalocrocis Medinalis ◽  
Lepidoptera Pyralidae

scholarly journals Extent of Variation of the Bacillus thuringiensis Toxin Reservoir: the Case of the Geranium Bronze, Cacyreus marshalli Butler (Lepidoptera: Lycaenidae)

2002 ◽  
Vol 68 (8) ◽  
pp. 4090-4094 ◽  
Author(s):  
Salvador Herrero ◽  
Marisé Borja ◽  
Juan Ferré
Keyword(s):  
Bacillus Thuringiensis ◽  
Binding Site ◽  
Management Strategies ◽  
Resistance Management ◽  
Cross Resistance ◽  
Binding Studies ◽  
Cry Proteins ◽  
Combined Use ◽  
The Common

ABSTRACT Despite the fact that around 200 cry genes from Bacillus thuringiensis have already been cloned, only a few Cry proteins are toxic towards a given pest. A crucial step in the mode of action of Cry proteins is binding to specific sites in the midgut of susceptible insects. Binding studies in insects that have developed cross-resistance discourage the combined use of Cry proteins sharing the same binding site. If resistance management strategies are to be implemented, the arsenal of Cry proteins suitable to control a given pest may be not so vast as it might seem at first. The present study evaluates the potential of B. thuringiensis for the control of a new pest, the geranium bronze (Cacyreus marshalli Butler), a butterfly that is threatening the popularity of geraniums in Spain. Eleven of the most common Cry proteins from the three lepidopteran-active Cry families (Cry1, Cry2, and Cry9) were tested against the geranium bronze for their toxicity and binding site relationships. Using 125I-labeled Cry1A proteins we found that, of the seven most active Cry proteins, six competed for binding to the same site. For the long-term control of the geranium bronze with B. thuringiensis-based insecticides it would be advisable to combine any of the Cry proteins sharing the binding site (preferably Cry1Ab, since it is the most toxic) with those not competing for the same site. Cry1Ba would be the best choice of these proteins, since it is significantly more toxic than the others not binding to the common site.

Identification of Bacillus thuringiensis Cry3Aa toxin domain II loop 1 as the binding site of Tenebrio molitor cadherin repeat CR12

2015 ◽  
Vol 59 ◽  
pp. 50-57 ◽  
Author(s):  
Fernando Zúñiga-Navarrete ◽  
Isabel Gómez ◽  
Guadalupe Peña ◽  
Itzel Amaro ◽  
Ernesto Ortíz ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Binding Site ◽  
Tenebrio Molitor

scholarly journals Location of the Bombyx mori 175 kDa cadherin-like protein-binding site on Bacillus thuringiensis Cry1Aa toxin

FEBS Journal ◽  
2008 ◽  
Vol 275 (19) ◽  
pp. 4913-4926 ◽  
Author(s):  
Shogo Atsumi ◽  
Yukino Inoue ◽  
Takahisa Ishizaka ◽  
Eri Mizuno ◽  
Yasutaka Yoshizawa ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Protein Binding ◽  
Binding Site ◽  
Bombyx Mori ◽  
Protein Binding Site

Evaluation of Pakistanian Bacillus thuringiensis isolates against Scirpophaga incertulas and Cnaphalocrocis medinalis

1999 ◽  
Vol 2 (1) ◽  
pp. 61-67
Author(s):  
Shahid Karim ◽  
Kausar Malik ◽  
Uzma Zafar ◽  
S. Riazuddin
Keyword(s):  
Bacillus Thuringiensis ◽  
Cnaphalocrocis Medinalis ◽  
Scirpophaga Incertulas

scholarly journals Binding Analyses of Bacillus thuringiensis Cry δ-Endotoxins Using Brush Border Membrane Vesicles of Ostrinia nubilalis

2001 ◽  
Vol 67 (2) ◽  
pp. 872-879 ◽  
Author(s):  
Gang Hua ◽  
Luke Masson ◽  
Juan Luis Jurat-Fuentes ◽  
George Schwab ◽  
Michael J. Adang
Keyword(s):  
Bacillus Thuringiensis ◽  
Binding Site ◽  
Brush Border ◽  
Ostrinia Nubilalis ◽  
European Corn Borer ◽  
Binding Proteins ◽  
Brush Border Membrane ◽  
Membrane Vesicles ◽  
Brush Border Membrane Vesicles ◽  
Cry Toxin

ABSTRACT Transgenic corn expressing the Bacillus thuringiensisCry1Ab gene is highly insecticidal to Ostrinia nubilalis(European corn borer) larvae. We ascertained whether Cry1F, Cry9C, or Cry9E recognizes the Cry1Ab binding site on the O. nubilalis brush border by three approaches. An optical biosensor technology based on surface plasmon resonance measured binding of brush border membrane vesicles (BBMV) injected over a surface of immobilized Cry toxin. Preincubation with Cry1Ab reduced BBMV binding to immobilized Cry1Ab, whereas preincubation with Cry1F, Cry9C, or Cry9E did not inhibit BBMV binding. BBMV binding to a Cry1F-coated surface was reduced when vesicles were preincubated in Cry1F or Cry1Ab but not Cry9C or Cry9E. A radioligand approach measured 125I-Cry1Ab toxin binding to BBMV in the presence of homologous (Cry1Ab) and heterologous (Cry1Ac, Cry1F, Cry9C, or Cry9E) toxins. Unlabeled Cry1Ac effectively competed for 125I-Cry1Ab binding in a manner comparable to Cry1Ab itself. Unlabeled Cry9C and Cry9E toxins did not inhibit 125I-Cry1Ab binding to BBMV. Cry1F inhibited125I-Cry1Ab binding at concentrations greater than 500 nM. Cry1F had low-level affinity for the Cry1Ab binding site. Ligand blot analysis identified Cry1Ab, Cry1Ac, and Cry1F binding proteins in BBMV. The major Cry1Ab signals on ligand blots were at 145 kDa and 154 kDa, but a strong signal was present at 220 kDa and a weak signal was present at 167 kDa. Cry1Ac and Cry1F binding proteins were detected at 220 and 154 kDa. Anti-Manduca sexta aminopeptidase serum recognized proteins of 145, 154, and 167 kDa, and anti-cadherin serum recognized the 220 kDa protein. We speculate that isoforms of aminopeptidase and cadherin in the brush border membrane serve as Cry1Ab, Cry1Ac, and Cry1F binding proteins.

scholarly journals Binding Site Alteration Is Responsible for Field-Isolated Resistance to Bacillus thuringiensis Cry2A Insecticidal Proteins in Two Helicoverpa Species

PLoS ONE ◽  
2010 ◽  
Vol 5 (4) ◽  
pp. e9975 ◽  
Author(s):  
Silvia Caccia ◽  
Carmen Sara Hernández-Rodríguez ◽  
Rod J. Mahon ◽  
Sharon Downes ◽  
William James ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Binding Site ◽  
Insecticidal Proteins
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