Interaction of
            <i>Bacillus thuringiensis</i>
            Cry1 and Vip3A Proteins with
            <i>Spodoptera frugiperda</i>
            Midgut Binding Sites

Sena, Janete Apparecida Desidério; Hernández‐Rodríguez, Carmen Sara; Ferré, Juan

doi:10.1128/aem.02342-08

Cited by 141 publications

(113 citation statements)

References 10 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%

“…10). Specific binding to brush border membrane vesicles (BBMVs) prepared from susceptible insects was first shown by using biotin-labeled Vip3Aa and Vip3Af (68,69,74,87,92,93,95). Interestingly, Vip3Aa also binds specifically to BBMVs of the nonsusceptible insect O. nubilalis (87), which indicates that specific binding is not sufficient to produce toxicity.…”

Section: Mode Of Actionmentioning

confidence: 99%

See 1 more Smart Citation

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%

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

show abstract

“…Cry1Fa is highly toxic to Ostrinia nubilalis, European corn borer, and has significant but not high-level toxicity to Spodoptera frugiperda, fall armyworm (46). Unfortunately, in Puerto Rico, where S. frugiperda is a major corn pest, S. frugiperda larvae have acquired resistance to Cry1Fa corn and the product was withdrawn from the market (26,47).…”

mentioning

confidence: 99%

Differential Protection of Cry1Fa Toxin against Spodoptera frugiperda Larval Gut Proteases by Cadherin Orthologs Correlates with Increased Synergism

Rahman

Abdullah

Ambati

et al. 2012

Appl Environ Microbiol

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The Cry proteins produced by Bacillus thuringiensis (Bt) are the most widely used biopesticides effective against a range of crop pests and disease vectors. Like chemical pesticides, development of resistance is the primary threat to the long-term efficacy of Bt toxins. Recently discovered cadherin-based Bt Cry synergists showed the potential to augment resistance management by improving efficacy of Cry toxins. However, the mode of action of Bt Cry synergists is thus far unclear. Here we elucidate the mechanism of cadherin-based Cry toxin synergism utilizing two cadherin peptides, Spodoptera frugiperda Cad (SfCad) and Manduca sexta Cad (MsCad), which differentially enhance Cry1Fa toxicity to Spodoptera frugiperda neonates. We show that differential SfCad-and MsCad-mediated protection of Cry1Fa toxin in the Spodoptera frugiperda midgut correlates with differential Cry1Fa toxicity enhancement. Both peptides exhibited high affinity for Cry1Fa toxin and an increased rate of Cry1Fa-induced pore formation in S. frugiperda. However, only SfCad bound the S. frugiperda brush border membrane vesicle and more effectively prolonged the stability of Cry1Fa toxin in the gut, explaining higher Cry1Fa enhancement by this peptide. This study shows that cadherin fragments may enhance B. thuringiensis toxicity by at least two different mechanisms or a combination thereof: (i) protection of Cry toxin from protease degradation in the insect midgut and (ii) enhancement of pore-forming ability of Cry toxin. Bacillus thuringiensis (Bt) Cry toxins are a family of bacterial pore-forming proteins that are highly toxic to a range of crop pests and disease vectors. Cry proteins are produced as crystals during the sporulation phase. Crystals are ingested, solubilized in the gut lumen to protoxin, and activated by host gut proteases. Activated toxin crosses the peritrophic matrix (PM) and binds cadherin, which is the primary high-affinity receptor for Cry1 toxins on the apical border of midgut microvilli. A current model postulates that toxin interaction with cadherin causes a conformational change in toxin allowing a specific proteolytic cleavage and formation of a prepore toxin oligomer. Evidence suggests that the prepore oligomer has increased affinity for secondary glycosylphosphatidylinositol (GPI)-anchored receptors, such as aminopeptidases (APNs) or alkaline phosphatases (ALPs) localized in lipid rafts. Oligomers insert into the membrane and disrupt membrane integrity by forming lytic pores, which lead directly to insect mortality or indirectly to mortality due to septicemia (5,7,21,45). A recent modification to the pore formation model described above proposes that activated toxin monomers first bind to abundant low-affinity APN receptors before binding to high-affinity cadherin receptors, which results in toxin oligomerization (32). In contrast to the pore formation model, the cell-signaling model (54) proposes that binding of activated toxin monomers to cadherin activates an intracellular signaling pathway, which ultimately results ...

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“…The members of the Vip3 family characterized to date exhibit activity against lepidopterans, and several of them do not compete with Cry proteins for binding sites (12,18). They are classified into two subfamilies (Vip3A and Vip3B), and some are especially toxic for species with little susceptibility to several Cry proteins (4,14).…”

mentioning

confidence: 99%