College of Plant Protection, Hebei Agricultural University, Baoding 071000, China.
Plant Science and Technology College, Beijing University of Agriculture, Beijing 102206, China.
Int J Mol Sci. 2017 Nov 30;18(12):2575. doi: 10.3390/ijms18122575.
The fall webworm, (Drury) is a major invasive pest in China. Aminopeptidase N (APN) isoforms in lepidopteran larvae midguts are known for their involvement in the mode of action of insecticidal crystal (Cry) proteins from . In the present work, we identified a putative Cry1Ab toxin-binding protein, an APN isoform designated HcAPN3, in the midgut of by ligand blot and mass spectrometry. was highly expressed throughout all larval developmental stages and was abundant in the midgut and hindgut tissues. was down-regulated at 6 h, then was up-regulated significantly at 12 h and 24 h after Cry1Ab toxin treatment. We expressed HcAPN3 in insect cells and detected its interaction with Cry1Ab toxin by ligand blot assays. Furthermore, RNA interference (RNAi) against using oral delivery and injection of double-stranded RNA (dsRNA) resulted in a 61-66% decrease in transcript level. Down-regulating of the expression of HcAPN3 was closely associated with reduced susceptibility of to Cry1Ab. In addition, the HcAPN3E fragment peptide expressed in enhanced Cry1Ab toxicity against larvae. This work represents the first evidence to suggest that an APN in is a putative binding protein involved in Cry1Ab susceptibility.
秋粘虫（Drury）是中国的一种主要入侵性害虫。鳞翅目幼虫中肠的氨肽酶 N（APN）同工型因其参与昆虫晶体（Cry）蛋白的作用模式而闻名。在本工作中，我们通过配体印迹和质谱法在中肠中鉴定了一种假定的 Cry1Ab 毒素结合蛋白，一种命名为 HcAPN3 的 APN 同工型。 在所有幼虫发育阶段均高度表达，在中肠和后肠组织中丰富。 在 Cry1Ab 毒素处理后 6 h 下调，然后在 12 h 和 24 h 时显著上调。我们在昆虫细胞中表达了 HcAPN3，并通过配体印迹测定检测了其与 Cry1Ab 毒素的相互作用。此外，通过口服和注射双链 RNA（dsRNA）对 HcAPN3 进行 RNA 干扰（RNAi）导致转录水平降低 61-66%。HcAPN3 的表达下调与 对 Cry1Ab 的敏感性降低密切相关。此外，在 中表达的 HcAPN3E 片段肽增强了 Cry1Ab 对 幼虫的毒性。这项工作首次表明， 中的一种 APN 是参与 Cry1Ab 敏感性的假定结合蛋白。
