Binding Sites for Bacillus thuringiensis Cry2Ae Toxin on Heliothine Brush Border Membrane Vesicles Are Not Shared with Cry1A, Cry1F, or Vip3A Toxin

Gouffon, C.; Vliet, Adri Van; Rie, Jeroen Van; Jansens, Stefan; Jurat-Fuentes, Juan Luís

doi:10.1128/aem.02791-10

Cited by 106 publications

(76 citation statements)

References 49 publications

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“…This has been shown for Vip3Aa with Cry1Ac, Cry1Ab, Cry1Fa, Cry2Ae, and Cry2Ab in all insect species tested and for Vip3Af with Cry1Ab and Cry1F in S. frugiperda (69,89,92,93,95,96 Fig. 11.…”

Section: Mode Of Actionmentioning

confidence: 99%

Bacterial Vegetative Insecticidal Proteins (Vip) from Entomopathogenic Bacteria

Chakroun

Banyuls

Bel

et al. 2016

Microbiol Mol Biol Rev

260

261

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SUMMARYEntomopathogenic bacteria produce insecticidal proteins that accumulate in inclusion bodies or parasporal crystals (such as the Cry and Cyt proteins) as well as insecticidal proteins that are secreted into the culture medium. Among the latter are the Vip proteins, which are divided into four families according to their amino acid identity. The Vip1 and Vip2 proteins act as binary toxins and are toxic to some members of the Coleoptera and Hemiptera. The Vip1 component is thought to bind to receptors in the membrane of the insect midgut, and the Vip2 component enters the cell, where it displays its ADP-ribosyltransferase activity against actin, preventing microfilament formation. Vip3 has no sequence similarity to Vip1 or Vip2 and is toxic to a wide variety of members of the Lepidoptera. Its mode of action has been shown to resemble that of the Cry proteins in terms of proteolytic activation, binding to the midgut epithelial membrane, and pore formation, although Vip3A proteins do not share binding sites with Cry proteins. The latter property makes them good candidates to be combined with Cry proteins in transgenic plants (Bacillus thuringiensis-treated crops [Bt crops]) to prevent or delay insect resistance and to broaden the insecticidal spectrum. There are commercially grown varieties of Bt cotton and Bt maize that express the Vip3Aa protein in combination with Cry proteins. For the most recently reported Vip4 family, no target insects have been found yet.

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Section: Mode Of Actionmentioning

confidence: 99%

Bacterial Vegetative Insecticidal Proteins (Vip) from Entomopathogenic Bacteria

Chakroun

Banyuls

Bel

et al. 2016

Microbiol Mol Biol Rev

260

261

View full text Add to dashboard Cite

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“…According to current models of Cry intoxication (38), smaller amounts of Cry1A toxin bound to the midgut may result in reduced toxin oligomerization and subsequent pore formation, explaining the reduced susceptibility. In support of the relevance of binding site concentration for susceptibility, positive associations have been reported for Cry1Ac and Cry1Ba during development of Manduca sexta larvae (36), for Cry1A and Cry2A toxins in Marasmia patnalis (39), and for Cry2Ae in H. zea and H. virescens (29).…”

Section: Discussionmentioning

confidence: 99%

“…Activated Cry1Ab, Cry1Ac, and Cry1Ca toxins (10 g) were radioiodinated with 0.5 mCi Na 125 I (PerkinElmer, Boston, MA) using chloramine T as previously described (29). Labeled toxins were purified from free iodine using a PD-10 desalting column (GE Healthcare Life Sciences) equilibrated in column buffer (20 mM TrisHCl, 150 mM NaCl, 0.1% bovine serum albumin [BSA], pH 8.65).…”

Section: Methodsmentioning

confidence: 99%

Binding Site Concentration Explains the Differential Susceptibility of Chilo suppressalis and Sesamia inferens to Cry1A-Producing Rice

Han

Liu

et al. 2014

Appl Environ Microbiol

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Chilo suppressalis and Sesamia inferens are two important lepidopteran rice pests that occur concurrently during outbreaks in paddy fields in the main rice-growing areas of China. Previous and current field tests demonstrate that the transgenic rice line Huahui 1 (HH1) producing a Cry1Ab-Cry1Ac hybrid toxin from the bacterium Bacillus thuringiensis reduces egg and larval densities of C. suppressalis but not of S. inferens. This differential susceptibility to HH1 rice correlates with the reduced susceptibility to Cry1Ab and Cry1Ac toxins in S. inferens larvae compared to C. suppressalis larvae. The goal of this study was to identify the mechanism responsible for this differential susceptibility. In saturation binding assays, both Cry1Ab and Cry1Ac toxins bound with high affinity and in a saturable manner to midgut brush border membrane vesicles (BBMV) from C. suppressalis and S. inferens larvae. While binding affinities were similar, a dramatically lower concentration of Cry1A toxin binding sites was detected for S. inferens BBMV than for C. suppressalis BBMV. In contrast, no significant differences between species were detected for Cry1Ca toxin binding to BBMV. Ligand blotting detected BBMV proteins binding Cry1Ac or Cry1Ca toxins, some of them unique to C. suppressalis or S. inferens. These data support that reduced Cry1A binding site concentration is associated with a lower susceptibility to Cry1A toxins and HH1 rice in S. inferens larvae than in C. suppressalis larvae. Moreover, our data support Cry1Ca as a candidate for pyramiding efforts with Cry1A-producing rice to extend the activity range and durability of this technology against rice stem borers.

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“…Although the intoxication pathways and molecular interactions of Cry toxins with insect midgut proteins are not fully understood, it has been well documented that the specific binding of different toxins to the midgut brush border membrane proteins varies, depending on the toxins and host insects (4,33,50). Cry1A and Cry2A toxins are known to bind to different binding sites in the insect midgut, and consequently, Cry1A resistance caused by binding site alteration (also known as "reduced toxin binding") usually does not exhibit cross-resistance to Cry2A toxins (22,23,51). In T. ni, it has been determined that binding site alteration-mediated Cry1Ac resistance does not confer resistance to Cry2Ab (18,32).…”

Section: Discussionmentioning

confidence: 99%

Resistance to Bacillus thuringiensis Toxin Cry2Ab in Trichoplusia ni Is Conferred by a Novel Genetic Mechanism

Song

Kain

Cassidy

et al. 2015

Appl Environ Microbiol

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The resistance to the Bacillus thuringiensis (Bt) toxin Cry2Ab in a greenhouse-originated Trichoplusia ni strain resistant to both Bt toxins Cry1Ac and Cry2Ab was characterized. Biological assays determined that the Cry2Ab resistance in the T. ni strain was a monogenic recessive trait independent of Cry1Ac resistance, and there existed no significant cross-resistance between Cry1Ac and Cry2Ab in T. ni. From the dual-toxin-resistant T. ni strain, a strain resistant to Cry2Ab only was isolated, and the Cry2Ab resistance trait was introgressed into a susceptible laboratory strain to facilitate comparative analysis of the Cry2Ab resistance with the susceptible T. ni strain. Results from biochemical analysis showed no significant difference between the Cry2Ab-resistant and -susceptible T. ni larvae in midgut proteases, including caseinolytic proteolytic activity and zymogram profile and serine protease activities, in midgut aminopeptidase and alkaline phosphatase activity, and in midgut esterases and hemolymph plasma melanization activity. For analysis of genetic linkage of Cry2Ab resistance with potential Cry toxin receptor genes, molecular markers for the midgut cadherin, alkaline phosphatase (ALP), and aminopeptidase N (APN) genes were identified between the original greenhouse-derived dual-toxin-resistant and the susceptible laboratory T. ni strains. Genetic linkage analysis showed that the Cry2Ab resistance in T. ni was not genetically associated with the midgut genes coding for the cadherin, ALP, and 6 APNs (APN1 to APN6) nor associated with the ABC transporter gene ABCC2. Therefore, the Cry2Ab resistance in T. ni is conferred by a novel but unknown genetic mechanism.T he Gram-positive soil bacterium Bacillus thuringiensis (Bt) has been widely used as a microbial insecticide in sprayable formulations, and Bt toxins are the primary insecticidal proteins expressed in genetically engineered crops to confer insect resistance (1; ISAAA's GM Approval Database, http://www.isaaa.org /gmapprovaldatabase/). Since the mid-1990s, insect-resistant Bt crops have been rapidly adopted with proven economic and environmental benefits (2, 3). However, development of insect resistance to Bt toxins threatens the long-term success of application of Bt toxins for insect pest control. The genetic potential of insect populations to evolve Bt resistance has been well shown in laboratory selections, and cases of insect resistance to Bt formulations and Bt crops have occurred in insect populations under selection pressure by Bt sprays and Bt crops in the field (4-8).Studies of insect resistance to Bt toxins have so far been mostly on Lepidoptera pests to the toxin Cry1Ab or Cry1Ac (9-19), the two major Bt Cry toxins which are highly toxic to Lepidoptera pests and known to share the same binding sites in target insects (4, 20). Cry1Ab and Cry1Ac are the primary insecticidal proteins expressed in the current commercial transgenic Bt maize and Bt cotton varieties to target Lepidoptera pests in the field (21). Resistance to Cry1Ac and Cry1Ab ...

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Binding Sites for Bacillus thuringiensis Cry2Ae Toxin on Heliothine Brush Border Membrane Vesicles Are Not Shared with Cry1A, Cry1F, or Vip3A Toxin

Cited by 106 publications

References 49 publications

Bacterial Vegetative Insecticidal Proteins (Vip) from Entomopathogenic Bacteria

Bacterial Vegetative Insecticidal Proteins (Vip) from Entomopathogenic Bacteria

Binding Site Concentration Explains the Differential Susceptibility of Chilo suppressalis and Sesamia inferens to Cry1A-Producing Rice

Resistance to Bacillus thuringiensis Toxin Cry2Ab in Trichoplusia ni Is Conferred by a Novel Genetic Mechanism

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