Difference between revisions of "Part:BBa K5066007"

Revision as of 07:20, 2 October 2024

Cyt2Ba-p20-Xpp81Aa1

Description

Insecticide resistance is becoming increasingly problematic and prominent in many Southeast Asian countries, areas where dengue fever is prevalent. The combination of Bt toxins and scorpion toxins is a promising strategy providing a potential layer of protection against insecticide resistance. The ribosome binding site(RBS) is a sequence of nucleotides before the start codon of an mRNA transcript and functions to recruit ribosomes for the translation of proteins. The histag,6X His, is a commonly used purification tag that contains 6 consecutive histidine residues. The His-tag can be stained with His-tag antibodies after translation, labelling the target recombinant protein. It is typically placed on either the N or C terminus of a protein. The strain also has its stop codons removed in order to increase the production of toxins. P20 is a chaperone that aids in the production of BTI toxins.

Fig 1. Plasmid construct design

Use in Biology

Cyt2ba is a toxin that binds to membrane receptors and increases membrane permeability. In Aedes aegypti, the toxin binds to the midgut of the mosquito larvae. Due to its crystalline structure, the toxin alters the cell membrane’s permeability which is crucial for cellular transport and activities, ultimately leading to the death of the larvae as a result of malnutrition and damage to the cell membrane.[1][2][3] Xpp81Aa is one of the Bacillus thuringiensis toxins, or Bt toxins, that derive from Bt bacteria and are commonly used as insecticides as they can target specific insects without causing harm to other species. There are a wide variety of strains derived from a selection of Bt bacteria and each has similar effects but targets different species of insects. Previous study has demonstrated its benefit in assisting the mortality rate of mosquito larvae is its symbiotic relationship with Bt toxins (such as Cry2Aa and Cry4Aa). Chosen for its coactive properties, Xpp81Aa heightens the effectiveness of the other toxins.[4]

Sequence and Features

Reference

[1] Bravo, A., Likitvivatanavong, S., Gill, S. S., & Soberón, M. (2011). Bacillus thuringiensis: A story of a successful bioinsecticide. Insect Biochemistry and Molecular Biology, 41(7), 423–431. https://doi.org/10.1016/j.ibmb.2011.02.006

[2] Wu, J., Wei, L., He, J., Fu, K., Li, X., Jia, L., Wang, R., & Zhang, W. (2021). Characterization of a novel Bacillus thuringiensis toxin active against Aedes aegypti larvae. Acta Tropica, 223, 106088. https://doi.org/10.1016/j.actatropica.2021.106088

[3] Gu, J.-B., Dong, Y.-Q., Peng, H.-J., & Chen, X.-G. (2010). A Recombinant AeDNA Containing the Insect-Specific Toxin, BmK IT1, Displayed an Increasing Pathogenicity on Aedes albopictus. American Journal of Tropical Medicine and Hygiene, 83(3), 614–623. https://doi.org/10.4269/ajtmh.2010.10-0074

[4]Wu, J., Wei, L., He, J., Fu, K., Li, X., Jia, L., Wang, R., & Zhang, W. (2021). Characterization of a novel Bacillus thuringiensis toxin active against Aedes aegypti larvae. Acta tropica, 223, 106088. https://doi.org/10.1016/j.actatropica.2021.106088