cadherin insect

Lipid homeostasis is crucial for growth and development of organisms. Several cytochrome P450 monooxygenases (CYPs) are involved in lipid metabolism. The function of Cyp311a1 in the anterior midgut as a regulator of phosphatidylethanolamine (PE) metabolism in Drosophila melanogaster has been demonstrated, as depletion of Cyp311a1 caused larval growth arrest that was partially rescued by supplying PE. In this study, we investigated the role of CYP311A1 in wing morphogenesis in Drosophila. Using the GAL4-UAS system, Cyp311a1 was selectively knocked down in the wing disc...

BACKGROUND: With the increasing incidence of pest resistance to transgenic crops producing Bacillus thuringiensis (Bt) proteins in the field, elucidating the molecular basis of resistance is important for monitoring, delaying, and countering pest resistance. Previous work revealed that mutation or downregulated expression of the cadherin gene (PgCad1) is associated with pink bollworm (Pectinophora gossypiella) resistance to Cry1Ac, and twenty mutant PgCad1 alleles (r1-r20) were characterized...

The widespread use of Bacillus thuringiensis toxins as insecticides has brought about resistance problems. Anti-idiotypic nanobody approaches provide new strategies for resistance management and toxin evolution. In this study, the monoclonal antibody generated against the receptor binding region Domain II of Cry2Aa toxin was used as a target to screen materials with insecticidal activity. After four rounds of screening, anti-idiotypic nanobody 1C12 was obtained from the natural alpaca nanobody phage display library...

The white potato worm Premnotrypes vorax (Hustache) (Coleoptera: Curculionidae) is one of the most destructive insect pests of potato crops in South America. Like many coleopteran insects, P. vorax shows low susceptibility to Cry insecticidal proteins produced by the bacterium Bacillus thuringiensis (Bt). However, the presence of Cry toxin receptors in the midgut of this this insect has never been studied. The main Cry-binding proteins described in other insect species are cadherin (CAD), aminopeptidase N (APN), alkaline phosphatase (ALP) and ATP-binding cassette (ABC) transporters...

Identifying the mechanisms by which bacterial pathogens kill host cells is fundamental to understanding how to control and prevent human and animal disease. In the case of Bacillus thuringiensis (Bt), such knowledge is critical to using the bacterium to kill insect vectors that transmit human and animal disease. For the Cry4B toxin produced by Bt, its capacity to kill Anopheles gambiae , the primary mosquito vector of malaria, is the consequence of a variety of signaling activities. We show here that Cry4B, acting as first messenger, binds specifically to the bitopic cadherin BT-R3 G-protein-coupled receptor (GPCR) localized in the midgut of A...

Detection of sex pheromones of insects relies on the antennae. The female pheromone signal transmission in the male antennae ultimately initiates the courtship and mating behaviors of males. To investigate the proteins and metabolites involved in this neural transduction, integrative proteomics and metabolomics analysis including tandem mass tag (TMT) proteomic quantification and liquid chromatography tandem mass spectrometry (LC/MS)-based metabolomics was adopted for comparing proteomic and metabolic changes between the antennae of male moths following stimulation by females and the non-stimulated males of Antheraea pernyi (Guérin-Méneville, Lepidoptera: Saturniidae) in this study...

Midgut receptors play a critical role in the specificity of Cry toxins for individual insect species. Cadherin proteins are essential putative receptors of Cry1A toxins in lepidopteran larvae. Cry2A family members share common binding sites in Helicoverpa armigera, and one of them, Cry2Aa, has been widely reported to interact with midgut cadherin. Here, we studied the binding interaction and functional role of H. armigera cadherin in the mechanism of Cry2Ab toxicity. A region spanning from cadherin repeat 6 (CR6) to the membrane-proximal region (MPR) of cadherin protein was produced as six overlapping peptides to identify the specific binding regions of Cry2Ab...

Bacillus thuringiensis (Bt) produces different insecticidal proteins effective for pest control. Among them, Cry insecticidal proteins have been used in transgenic plants for the control of insect pests. However, evolution of resistance by insects endangers this technology. Previous work showed that the lepidopteran insect Plutella xylostella PxHsp90 chaperone enhanced the toxicity of Bt Cry1A protoxins by protecting them from degradation by the larval gut proteases and by enhancing binding of the protoxin to its receptors present in larval midgut cells...

Transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) control some important insect pests. However, evolution of resistance by pests reduces the efficacy of Bt crops. Here we review resistance to Bt cotton in the pink bollworm, Pectinophora gossypiella , one of the world's most damaging pests of cotton. Field outcomes with Bt cotton and pink bollworm during the past quarter century differ markedly among the world's top three cotton-producing countries: practical resistance in India, sustained susceptibility in China, and eradication of this invasive lepidopteran pest from the United States achieved with Bt cotton and other tactics...

Lepidopteran insect pest Helicoverpa armigera is one of the most destructive pests of crop plants and several biotechnological approaches are being developed for its control. Plant defensins are small cationic and cysteine-rich peptides that play a role in plant defense. Ingestion of a defensin from Capsicum annuum (CanDef-20) induced a dose-dependent reduction in larval and pupal mass, delayed metamorphosis and also severely reduced fecundity and fertility in H. armigera. To understand the molecular mechanisms of CanDef-20 ingestion-mediated antibiosis in H...

Cotton has been one of the most important cash crops in Pakistan, but its production is adversely affected by biotic and abiotic stresses. Insect pests such as pink bollworm present a colossal vulnerability to such a financially important commodity. Bt toxins have been widely used to safeguard agricultural plants against notorious insect pests such as cotton bollworm and pink bollworm, and they have proven to be effective in reducing chewing insect pests. However, its efficacy has been challenged due to the development of resistance in insect pests against Bt toxins such as cry1Ac and this poses a significant risk to the long-term adoption of these Bt crops...

Insect immunity defends the infection of an insect pathogenic bacterium, Bacillus thuringiensis (Bt). However, it was not clear on the recognition of Bt infection by the insect immune system. This study tested a physiological function of dorsal switch protein 1 (DSP1) in the Bt infection. DSP1 is classified into HMGB1-like damage-associated molecular pattern (DAMP) in insects. Upon Bt infection in a lepidopteran Spodoptera exigua, DSP1 was released from the nuclei of the midgut epithelium and activated immune responses...

The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is an economically important pest of corn (maize) in North America and Europe. Current management practices for WCR involve transgenic expression of insecticidal proteins to minimize larval feeding damage to corn roots. The evolution of resistant WCR populations to transgenic corn expressing insecticidal proteins (e.g. Cry3Bb1, Gpp34Ab1/Tpp35Ab1) necessitates efforts to discover and deploy new modes of action for WCR control...

New insecticidal genes and approaches for pest control are a hot research area. In the present study, we explored a novel strategy for the generation of insecticidal proteins. The midgut cadherin of Helicoverpa armigera ( H. armigera ) was used as a target to screen materials that have insecticidal activity. After three rounds of panning, the phage-displayed human domain antibody B1F6, which not only binds to the H. armigera cadherin CR9-CR11 but also significantly inhibits Cry1Ac toxins from binding to CR9-CR11, was obtained from a phage-displayed human domain antibody (DAb) library...

Two-partner secretion (TPS) is widespread in the bacterial world. The pore-forming TPS toxin ExlA of Pseudomonas aeruginosa is conserved in pathogenic and environmental Pseudomonas . While P. chlororaphis and P. entomophila displayed ExlA-dependent killing, P. putida did not cause damage to eukaryotic cells. ExlA proteins interacted with epithelial cell membranes; however, only ExlA Pch induced the cleavage of the adhesive molecule E-cadherin. ExlA proteins participated in insecticidal activity toward the larvae of Galleria mellonella and the fly Drosophila melanogaster...

Juvenile hormone (JH) acts as a gonadotrophic hormone stimulating insect vitellogenesis and oogenesis. Paracellular transport of yolk proteins through intercellular channels (patency) in the follicular epithelium is a developmentally regulated and evolutionarily conserved process during vitellogenesis. However, the mechanisms underlying patency opening are poorly understood. Using the migratory locust Locusta migratoria as a model system, we report here that JH-regulated remodeling of zonula adherens (ZA), the belt-like adherens junction maintaining physical linking between follicle cells controlled the opening of patency...

Transgenic crops producing Bacillus thuringiensis (Bt) insecticidal proteins are grown widely for pest control, but the evolution of resistance in target pests could reduce their efficacy. Mutations in genes encoding cadherin, ABC transporter or tetraspanin were linked with resistance to Cry1Ac in several lepidopteran insects, including the cotton bollworm ( Helicoverpa armigera ), a worldwide agricultural pest. However, the detailed molecular mechanisms by which these mutations confer insect resistance to Cry1Ac remain largely unknown...

Aedes aegypti is one of the world's most dangerous mosquitoes, and a vector of diseases such as dengue fever, chikungunya virus, yellow fever, and Zika virus disease. Currently, a major global challenge is the scarcity of antiviral medicine and vaccine for arboviruses. Bacillus thuringiensis var israelensis ( Bti ) toxins are used as biological mosquito control agents. Endotoxins, including Cry4Aa, Cry4Ba, Cry10Aa, Cry11Aa, and Cyt1Aa, are toxic to mosquitoes. Insect eradication by Cry toxin relies primarily on the interaction of cry toxins with key toxin receptors, such as aminopeptidase (APN), alkaline phosphatase (ALP), cadherin (CAD), and ATP-binding cassette transporters...

The Bacillus thuringiensis ( Bt ) Cry proteins are widely used in insect pest control. Despite their economic benefits, remaining concerns over potential ecological and health risks warrant their ongoing surveillance. Affinity reagents, most often antibodies, protein scaffolds, and aptamers, are the traditional tools used for protein binding and detection. We report a synthetic antibody (SA) alternative to traditional biological affinity reagents for binding Bt Cry proteins. Analysis of hotspots of the Bt Cry protein-insect midgut cadherin-like receptor complexes was used for the design of the SA...

The G-protein-coupled receptor BT-R1 in the moth Manduca sexta represents a class of single-membrane-spanning α-helical proteins within the cadherin family that regulate intercellular adhesion and contribute to important signaling activities that control cellular homeostasis. The Cry1A toxins, Cry1Aa, Cry1Ab, and Cry1Ac, produced by Bacillus thuringiensis bind BT-R1 very tightly ( K d = 1.1 nM) and trigger a Mg2+ -dependent signaling pathway that involves the stimulation of G-protein α-subunit, which subsequently launches a coordinated signaling cascade, resulting in insect death...