Mosquito midgut epithelial receptor complex

The mosquito midgut epithelial receptor complex, primarily located within the lipid bilayer of larval midgut cells, is the physiological target for insecticidal Crystal (Cry) toxins produced by Bacillus thuringiensis (Bravo et al., 2007, Toxicon). These toxins are ingested by mosquito larvae and undergo proteolytic activation in the alkaline environment of the midgut to become toxic fragments (Vachon et al., 2012, J. Invertebr. Pathol.). The activated toxins bind to specific high-affinity receptors anchored in the membrane, such as cadherin-like proteins, aminopeptidase N (APN), and alkaline phosphatase (ALP) (Likitvivatanavong et al., 2011, Appl. Environ. Microbiol.). Upon binding, the toxins undergo a conformational change that promotes oligomerization and insertion into the epithelial lipid bilayer to form stable, ion-selective pores (Soberón et al., 2009, Science). These pores disrupt the transmembrane potential and osmotic balance, leading to massive cell lysis, destruction of the midgut epithelium, and larval death. This mechanism is a cornerstone of biological vector control strategies used to reduce the transmission of diseases like malaria, dengue, and Zika virus.

Other names

Mosquito gut epithelial lipid bilayer and Cry toxinsCry toxin receptorsMidgut brush border membrane vesiclesBBMVBt toxin target

Pore formation and osmotic lysis of midgut epithelial cells following toxin-receptor binding and membrane insertion.