Cadherin-like protein (CAD)

Cadherin-like proteins are high-molecular-weight transmembrane glycoproteins located on the apical microvilli of insect midgut epithelial cells. They belong to the cadherin superfamily and are characterized by multiple extracellular cadherin repeats (CRs), a single transmembrane domain, and a cytoplasmic tail. While their endogenous roles involve cell-cell adhesion and midgut development, they are primarily recognized as the essential receptors for Bacillus thuringiensis (Bt) Cry toxins, such as the Cry1A family. Binding of these toxins to specific CR domains triggers a cascade of events, including toxin oligomerization and pore formation or signal-mediated cell death, which leads to the destruction of the midgut lining and subsequent death of the insect. Mutations in the genes encoding these proteins, such as deletions or truncations, are a primary mechanism by which agricultural pests develop resistance to Bt-expressing transgenic crops.

Other names

Bt-R1BtRCry toxin receptorCadherin-like receptorHevCaLPHaCadBtR175

Binding of Cry toxins to the cadherin receptor facilitates proteolytic activation, oligomerization, and pore formation in the midgut membrane, or triggers a G protein-mediated cell death signaling pathway.