Scavenger Receptor C1 Mediates Toxicity of Binary Toxin from to Ag55 Cells.

harboring Binary (BinA and BinB) toxins is highly toxic against and mosquito larvae. The Ag55 cell line is a suitable model for investigating the mode of Bin toxin action. Based on the low-levels of α-glycosidase Agm3 mRNA in Ag55 cells and the absence of detectable Agm3 proteins, we hypothesized that a scavenger receptor could be mediating Bin cytotoxicity.

A novel spider venom peptide from the predatory mite Neoseiulus barkeri shows lethal effect on phytophagous pests.

The long-term use of pesticides in the field, and the high fertility and adaptability of phytophagous mites have led to resistance problems; consequently, novel safe and efficient active substances are necessary to broaden the tools of pest mite control. Natural enemies of arthropods typically secrete substances with paralytic or lethal effects on their prey, and those substances are a resource for future biopesticides. In this study, two putative venom peptide genes were identified in a parasitic mite Neoseiulus barkeri transcriptome.

Anopheles gambiae strain (Ag55) cultured cells originated from Anopheles coluzzii and are phagocytic with hemocyte-like gene expression.

Anopheles gambiae and Anopheles coluzzii are closely related species that are predominant vectors of malaria in Africa. Recently, A. gambiae form M was renamed A.

Transcription factors CncC and Maf connect the molecular network between pesticide resistance and resurgence of pest mites.

Pesticide resistance and resurgence are serious problems often occurring simultaneously in the field. In our long-term study of a fenpropathrin-resistant strain of Tetranychus cinnabaribus, enhancement of detoxification and modified fecundity mechanisms were both observed. Here we investigate the network across these two mechanisms and find a key node between resistance and resurgence.

Novel strategies for the biocontrol of noctuid pests (Lepidoptera) based on improving ascovirus infectivity using Bacillus thuringiensis.

Identifying novel biocontrol agents and developing new strategies are urgent goals in insect pest biocontrol. Ascoviruses are potential competent insect viruses that may be developed into bioinsecticides, but this aim is impeded by their poor oral infectivity. To improve the per os infectivity of ascovirus, Bacillus thuringiensis kurstaki (Btk) was employed as a helper to damage the midgut of lepidopteran larvae (Helicoverpa armigera, Mythimna separata, Spodoptera frugiperda, and S.

Identification of Lysinibacillus sphaericus Binary toxin binding proteins in a malarial mosquito cell line by proteomics: A novel approach towards improving mosquito control.

Bacterial insecticidal proteins, such as the Bin toxin from Lysinibacillus sphaericus, could be used more extensively to control insecticide resistant mosquitoes. This study was aimed at identification of mosquito cell proteins binding Bin toxin. Results showed that purified toxin was toxic to Anopheles gambiae larvae and Ag55 cultured cells.

Fluorescent analyses of Bacillus thuringiensis Cry1Fa and Cry1Ab toxin binding sites on brush border membrane vesicles of Ostrinia nubilalis (Hübner), Diatraea grandiosella (Dyar), and Helicoverpa zea (Boddie) larvae.

Bacillus thuringiensis (Bt) Cry1Fa and Cry1Ab proteins are important Cry toxins due to their high, selective toxicity against a number of lepidopteran species, including important pests of corn and cotton. Competition binding assays are a classical tool for investigating Cry toxin interactions with target pest insects. We developed a fluorescence-based binding assay and assessed Cry1Fa and Cry1Ab toxin binding to brush border membrane preparations from lepidopteran corn pests including Ostrinia nubilalis (European corn borer, ECB), Diatraea grandiosella (south western corn borer, SWCB), and Helicoverpa zea (corn earworm, CEW).

Binding and Synergizing Motif within Coleopteran Cadherin Enhances Cry3Bb Toxicity on the Colorado Potato Beetle and the Lesser Mealworm.

Cry3Bb toxin from is an important insecticidal protein due to its potency against coleopteran pests, especially rootworms. Cadherin, a protein in the insect midgut epithelium, is a receptor of Cry toxins; in some insect species toxin-binding domains of cadherins-synergized Cry toxicity. Previously, we reported that the DvCad1-CR8-10 fragment of cadherin-like protein (GenBank Accession #EF531715) enhanced Cry3Bb toxicity to the Colorado Potato Beetle (CPB), ().

Identification of Cry48Aa/Cry49Aa toxin ligands in the midgut of Culex quinquefasciatus larvae.

A binary mosquitocidal toxin composed of a three-domain Cry-like toxin (Cry48Aa) and a binary-like toxin (Cry49Aa) was identified in Lysinibacillus sphaericus. Cry48Aa/Cry49Aa has action on Culex quinquefasciatus larvae, in particular, to those that are resistant to the Bin Binary toxin, which is the major insecticidal factor from L. sphaericus-based biolarvicides, indicating that Cry48Aa/Cry49Aa interacts with distinct target sites in the midgut and can overcome Bin toxin resistance.

High throughput sequencing reveals Drosophila suzukii responses to insecticides.

Global climate change and acquired resistance to insecticides are threats to world food security. Drosophila suzukii, a devastating invasive pest in many parts of the world, causes substantial economic losses to fruit production industries, forcing farmers to apply broad-spectrum insecticides frequently. This could lead to the development of insecticide resistance.

Effects and mechanisms of Bacillus thuringiensis crystal toxins for mosquito larvae.

Bacillus thuringiensis is a Gram-positive aerobic bacterium that produces insecticidal crystalline inclusions during sporulation phases of the mother cell. The virulence factor, known as parasporal crystals, is composed of Cry and Cyt toxins. Most Cry toxins display a common 3-domain topology.

Anopheles gambiae Ag55 cell line as a model for Lysinibacillus sphaericus Bin toxin action.

Binary toxin (Bin) produced by Lysinibacillus sphaericus is toxic to Culex and Anopheles mosquito larvae. It has been used world-wide for control of mosquitoes that vector disease. The Bin toxin interacts with the glucosidase receptor, Cpm1, in Culex and its orthologue, Agm3, in Anopheles mosquitoes.

Generation of a Transcriptome in a Model Lepidopteran Pest, Heliothis virescens, Using Multiple Sequencing Strategies for Profiling Midgut Gene Expression.

Heliothine pests such as the tobacco budworm, Heliothis virescens (F.), pose a significant threat to production of a variety of crops and ornamental plants and are models for developmental and physiological studies. The efforts to develop new control measures for H.

Crystal structure of Cry51Aa1: A potential novel insecticidal aerolysin-type β-pore-forming toxin from Bacillus thuringiensis.

The structures of several Bacillus thuringiensis (Bt) insecticidal crystal proteins have been determined by crystallographic methods and a close relationship has been explicated between specific toxicities and conserved three-dimensional architectures. In this study, as a representative of the coleopteran- and hemipteran-specific Cry51A group, the complete structure of Cry51Aa1 protoxin has been determined by X-ray crystallography at 1.65 Å resolution.

Chitosan/DsiRNA nanoparticle targeting identifies AgCad1 cadherin in Anopheles gambiae larvae as an in vivo receptor of Cry11Ba toxin of Bacillus thuringiensis subsp. jegathesan.

The Cry11Ba protein of Bacillus thuringiensis subsp. jegathesan crystals has uniquely high toxicity against a spectrum of mosquito species. The high potency of Cry11Ba against Anopheles gambiae is caused by recognition of multiple midgut proteins including glycosyl phosphatidylinositol-anchored alkaline phosphatase AgALP1, aminopeptidase AgAPN2, α-amylase AgAmy1 and α-glucosidase Agm3 that bind Cry11Ba with high affinity and function as putative receptors.

Bt toxin modification for enhanced efficacy.

Insect-specific toxins derived from Bacillus thuringiensis (Bt) provide a valuable resource for pest suppression. Here we review the different strategies that have been employed to enhance toxicity against specific target species including those that have evolved resistance to Bt, or to modify the host range of Bt crystal (Cry) and cytolytic (Cyt) toxins. These strategies include toxin truncation, modification of protease cleavage sites, domain swapping, site-directed mutagenesis, peptide addition, and phage display screens for mutated toxins with enhanced activity.

A coleopteran cadherin fragment synergizes toxicity of Bacillus thuringiensis toxins Cry3Aa, Cry3Bb, and Cry8Ca against lesser mealworm, Alphitobius diaperinus (Coleoptera: Tenebrionidae).

The lesser mealworm, Alphitobius diaperinus, is a serious cosmopolitan pest of commercial poultry facilities because of its involvement in structural damage to poultry houses, reduction in feed conversion efficiency, and transfer of avian and human pathogens. Cry3Aa, Cry3Bb, and Cry8Ca insecticidal proteins of Bacillus thuringiensis are used to control coleopteran larvae. Cadherins localized in the midgut epithelium function as receptors for Cry toxins in lepidopteran, coleopteran, and dipteran insects.

Cadherin AdCad1 in Alphitobius diaperinus larvae is a receptor of Cry3Bb toxin from Bacillus thuringiensis.

Bacillus thuringiensis (Bt) Cry proteins are used as components of biopesticides or expressed in transgenic crops to control diverse insect pests worldwide. These Cry toxins bind to receptors on the midgut brush border membrane and kill enterocytes culminating in larval mortality. Cadherin proteins have been identified as Cry toxin receptors in diverse lepidopteran, coleopteran, and dipteran species.

Analyses of α-amylase and α-glucosidase in the malaria vector mosquito, Anopheles gambiae, as receptors of Cry11Ba toxin of Bacillus thuringiensis subsp. jegathesan.

Bacillus thuringiensis subsp. jegathesan produces Cry11Ba crystal protein with high toxicity to mosquito larvae. The Cry11Ba toxicity is dependent on its receptors on mosquito larval midgut epithelial cells.

Proteome analysis of Cry4Ba toxin-interacting Aedes aegypti lipid rafts using geLC-MS/MS.

Lipid rafts are microdomains in the plasma membrane of eukaryotic cells. Among their many functions, lipid rafts are involved in cell toxicity caused by pore forming bacterial toxins including Bacillus thuringiensis (Bt) Cry toxins. We isolated lipid rafts from brush border membrane vesicles (BBMV) of Aedes aegypti larvae as a detergent resistant membrane (DRM) fraction on density gradients.

Differential protection of Cry1Fa toxin against Spodoptera frugiperda larval gut proteases by cadherin orthologs correlates with increased synergism.

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.

Synergistic and inhibitory effects of aminopeptidase peptides on Bacillus thuringiensis Cry11Ba toxicity in the mosquito Anopheles gambiae.

Cry11Ba produced by Bacillus thuringiensis subsp. jegathesan is an active toxin for larvae of the mosquito Anopheles gambiae. A 106-kDa aminopeptidase N (APN), called AgAPN2, was previously identified as a Cry11Ba receptor in A.

Cadherin fragments from Anopheles gambiae synergize Bacillus thuringiensis Cry4Ba's toxicity against Aedes aegypti larvae.

A peptide from cadherin AgCad1 of Anopheles gambiae larvae was reported as a synergist of Bacillus thuringiensis subsp. israelensis Cry4Ba's toxicity to the Anopheles mosquito (G. Hua, R.