A Novel Tenebrio molitor Cadherin Is a Functional Receptor for Bacillus thuringiensis Cry3Aa Toxin
A Novel Tenebrio molitor Cadherin Is a Functional Receptor for Bacillus thuringiensis Cry3Aa Toxin
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DOI：
10.1074/jbc.m109.001651
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发表时间：
2009-07-03
影响因子：
4.8
通讯作者：
Jurat-Fuentes, Juan Luis
中科院分区：
文献类型：
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作者：
Fabrick, Jeff;Oppert, Cris;Jurat-Fuentes, Juan Luis
苏云金芽孢杆菌产生的毒素是一种有效的生物杀虫剂。类钙粘附素蛋白是鳞翅目昆虫中具有功能的Cry1a毒素受体。在这里，我们提供的数据表明，鞘翅目钙粘附素是一种功能性的Cry3Aa毒素受体。从黄粉虫幼虫中肠基因中克隆了Cry3Aa受体钙粘蛋白，其编码蛋白TmCad1具有结构域结构和与苏云金芽孢杆菌受体相似的毒素结合区。一种含有TmCad1毒素结合区的多肽，能与Cry3Aa特异结合，并促进Cry3Aa毒素寡聚体的形成，被认为是鳞翅目昆虫毒性的介导物。将TmCad1特异的双链RNA注射到黄粉虫幼虫体内，导致TmCad1转录本的下调，并使其对Cry3Aa毒害产生抗性。这些数据证明了TmCad1作为一种Cry3Aa受体在二化螟中的功能作用，并揭示了Cry毒素在鳞翅目和鞘翅目中的作用模式的相似性。
Cry toxins produced by the bacterium Bacillus thuringiensis are effective biological insecticides. Cadherin-like proteins have been reported as functional Cry1A toxin receptors in Lepidoptera. Here we present data that demonstrate that a coleopteran cadherin is a functional Cry3Aa toxin receptor. The Cry3Aa receptor cadherin was cloned from Tenebrio molitor larval midgut mRNA, and the predicted protein, TmCad1, has domain structure and a putative toxin binding region similar to those in lepidopteran cadherin B. thuringiensis receptors. A peptide containing the putative toxin binding region from TmCad1 bound specifically to Cry3Aa and promoted the formation of Cry3Aa toxin oligomers, proposed to be mediators of toxicity in lepidopterans. Injection of TmCad1-specific double-stranded RNA into T. molitor larvae resulted in knockdown of the TmCad1 transcript and conferred resistance to Cry3Aa toxicity. These data demonstrate the functional role of TmCad1 as a Cry3Aa receptor in T. molitor and reveal similarities between the mode of action of Cry toxins in Lepidoptera and Coleoptera.