黄粉虫幼虫中的 Cadherin AdCad1 是苏云金芽孢杆菌 Cry3Bb 毒素的受体。
Cadherin AdCad1 in Alphitobius diaperinus larvae is a receptor of Cry3Bb toxin from Bacillus thuringiensis.
机构信息
Department of Entomology, University of Georgia, Athens, GA 30602-2603, USA.
Department of Entomology, University of Georgia, Athens, GA 30602-2603, USA; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602-2603, USA.
出版信息
Insect Biochem Mol Biol. 2014 Feb;45:11-7. doi: 10.1016/j.ibmb.2013.10.007. Epub 2013 Nov 10.
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. In the present work we report a 185 kDa cadherin (AdCad1) from larvae of the lesser mealworm (Alphitobius diaperinus) larvae as the first identified receptor for Cry3Bb toxin. The AdCad1 protein contains typical structural components for Cry toxin receptor cadherins, including nine cadherin repeats (CR9), a membrane-proximal extracellular domain (MPED) and a cytosolic region. Peptides corresponding to the CR9 and MPED regions bound Cry3Bb toxin with high affinities (23 nM and 40 nM) and significantly synergized Cry3Bb toxicity against A. diperinus larvae. Silencing of AdCad1 expression through RNA interference resulted in highly reduced susceptibility to Cry3Bb in A. diperinus larvae. The CR9 peptide fed with toxin to RNAi-treated larvae restored Cry3Bb toxicity. These results are evidences that AdCad1 is a functional receptor of Cry3Bb toxin and that exogenously fed CR9 peptide can overcome the effect of reduced AdCad1expression on Cry3Bb toxicity to larvae.
苏云金芽孢杆菌（Bt）Cry 蛋白被用作生物农药的成分，或在转基因作物中表达，以控制全球范围内的多种昆虫害虫。这些 Cry 毒素与中肠刷状缘膜上的受体结合，并杀死肠细胞，最终导致幼虫死亡。钙粘蛋白已被确定为多种鳞翅目、鞘翅目和双翅目昆虫中 Cry 毒素的受体。在本工作中，我们报道了小菜蛾（Alphitobius diaperinus）幼虫中的一种 185 kDa 钙粘蛋白（AdCad1），它是第一个被鉴定为 Cry3Bb 毒素受体的蛋白。AdCad1 蛋白包含 Cry 毒素受体钙粘蛋白的典型结构成分，包括九个钙粘蛋白重复序列（CR9）、一个膜近端细胞外结构域（MPED）和一个胞质区。与 CR9 和 MPED 区域相对应的肽与 Cry3Bb 毒素具有高亲和力（23 nM 和 40 nM），并显著增强了 Cry3Bb 对小菜蛾幼虫的毒性。通过 RNA 干扰沉默 AdCad1 表达，导致小菜蛾幼虫对 Cry3Bb 的敏感性显著降低。用毒素饲喂 CR9 肽给经 RNAi 处理的幼虫可恢复 Cry3Bb 的毒性。这些结果表明，AdCad1 是 Cry3Bb 毒素的功能性受体，并且外源性饲喂的 CR9 肽可以克服 AdCad1 表达减少对 Cry3Bb 毒性的影响。
Zotero 插件