Photorhabdus luminescens PirAB-fusion protein exhibits both cytotoxicity and insecticidal activity
Photorhabdus luminescens PirAB-fusion protein exhibits both cytotoxicity and insecticidal activity
复制标题
发光杆菌 PirAB 融合蛋白具有细胞毒性和杀虫活性
DOI：
10.1111/1574-6968.12474
复制
发表时间：
2014-07-01
影响因子：
2.1
通讯作者：
Hu, Shengbiao
中科院分区：
文献类型：
--
作者：
Li, Yusheng;Hu, Xiaofeng;Hu, Shengbiao
据报道，发光杆菌产生的二元毒素“发光杆菌昆虫相关”蛋白（PirAB）对一系列昆虫具有注射和口服活性。这里，通过将pirA和pirB基因与柔性接头（Gly（4）Ser）（3）DNA编码序列连接，构建PirAB融合蛋白，然后在大肠杆菌中有效表达。为了更好地理解PirAB毒素在入侵过程中发挥的作用，研究了其对昆虫中肠CF-203细胞的细胞毒性。纯化的PirAB融合蛋白以及PirA/PirB混合物的应用导致CF-203细胞在孵育24小时后丧失活力。CF-203细胞经PirAB融合蛋白处理后，出现典型的凋亡形态学改变，如细胞皱缩、细胞膜起泡、核固缩、DNA断裂等。此外，PirAB-融合蛋白还表现出对甜菜夜蛾幼虫的注射杀虫活性。S.注射PirAB融合蛋白的甜菜四龄幼虫完全变黑。因此，我们得出结论，PirAB融合蛋白具有与PirA/PirB混合物相似的生物活性（细胞毒性和杀虫活性），这将使其能够用作害虫防治的有效试剂。
The binary toxin `Photorhabdus insect-related' proteins (PirAB) produced by Photorhabdus luminescens have been reported to possess both injectable and oral activities against a range of insects. Here, PirAB-fusion protein was constructed by linking pirA and pirB genes with the flexible linker (Gly(4)Ser)(3) DNA encoding sequence and then efficiently expressed in Escherichia coli. To better understand the role of PirAB toxin played in the process of invasion, its cytotoxicity against insect midgut CF-203 cells was investigated. Application of purified PirAB-fusion protein as well as PirA/PirB mixture caused loss of viability of CF-203 cells after 24 h incubation. CF-203 cells treated by PirAB-fusion protein displayed morphological changes typical of apoptosis, such as cell shrinkage, cell membrane blebbing, nuclear condensation and DNA fragmentation. Moreover, PirAB-fusion protein also exhibited injectable insecticidal activity against Spodoptera exigua larvae. The bodies of S. exigua fourth-instar larvae injected with PirAB-fusion protein turned completely black. Thus, we concluded that PirAB-fusion protein possessed similar biological activity (cytotoxicity and insecticidal activity) to PirA/PirB mixture, which would enable it to be used as an efficient agent for pest control.