College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350000, China.
CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Bull Entomol Res. 2023 Oct;113(5):615-625. doi: 10.1017/S0007485323000299. Epub 2023 Jul 19.
is a quarantine pest that mainly damages plants in tropical regions, which are essential economic resources. Cry3Aa has been used to control coleopteran pests and is known to be toxic to . The binding of the Cry toxin to specific receptors on the target insect plays a crucial role in the toxicological mechanism of Cry toxins. However, in the case of , the nature and identity of the receptor proteins involved remain unknown. In the present study, pull-down assays and mass spectrometry were used to identify two proteins of aminopeptidase N proteins (RfAPN2a and RfAPN2b) in the larval midguts of . Cry3Aa was able to bind to RfAPN2a ( = 108.5 n) and RfAPN2b ( = 68.2 n), as well as midgut brush border membrane vesicles ( = 482.5 n). analysis of both RfAPN proteins included the signal peptide and anchored sites for glycosyl phosphatidyl inositol. In addition, RfAPN2a and RfAPN2b were expressed in the human embryonic kidney 293T cell line, and cytotoxicity assays showed that the transgenic cells were not susceptible to activated Cry3Aa. Our results show that RfAPN2a and RfAPN2b are Cry3Aa-binding proteins involved in the Cry3Aa toxicity of . This study deepens our understanding of the action mechanism of Cry3Aa in larvae.
是一种检疫性害虫，主要危害热带地区的植物，这些植物是重要的经济资源。Cry3Aa 被用于防治鞘翅目害虫，已知对 有毒。Cry 毒素与靶昆虫上特定受体的结合在 Cry 毒素的毒理学机制中起着至关重要的作用。然而，在 的情况下，涉及的受体蛋白的性质和身份仍然未知。在本研究中，采用下拉测定和质谱法鉴定了 幼虫中两种氨肽酶 N 蛋白（RfAPN2a 和 RfAPN2b）。Cry3Aa 能够与 RfAPN2a（=108.5n）和 RfAPN2b（=68.2n）结合，以及中肠刷状缘膜囊泡（=482.5n）结合。对两种 RfAPN 蛋白的 分析包括信号肽和糖基磷脂酰肌醇的锚定位点。此外，RfAPN2a 和 RfAPN2b 在人胚肾 293T 细胞系中表达，细胞毒性测定表明，转染细胞对激活的 Cry3Aa 不敏感。我们的结果表明，RfAPN2a 和 RfAPN2b 是 Cry3Aa 结合蛋白，参与了 Cry3Aa 对 的毒性。本研究加深了我们对 Cry3Aa 在 幼虫中的作用机制的理解。
