A venom protein, Kazal-type serine protease inhibitor, of ectoparasitoid Pachycrepoideus vindemiae inhibits the hemolymph melanization of host Drosophila melanogaster.
A venom protein, Kazal-type serine protease inhibitor, of ectoparasitoid Pachycrepoideus vindemiae inhibits the hemolymph melanization of host Drosophila melanogaster.
复制标题
DOI：
10.1002/arch.21736
复制
发表时间：
2020-09
影响因子：
2.2
通讯作者：
Lei Yang;Liming Qiu;Qi Fang;G. Yè
中科院分区：
文献类型：
--
作者：
Lei Yang;Liming Qiu;Qi Fang;G. Yè
寄生蜂在产卵过程中向寄主昆虫体内注入多种毒力因子，其中毒蛋白是影响寄主昆虫与寄生蜂关系的关键因子之一，参与宿主细胞免疫和体液免疫调节，保证寄生蜂后代的顺利发育。虽然对毒液蛋白在寄生蜂幼虫中作用的研究已经比较充分，但在蛹中的调控机制还不完全清楚。在这里，我们确定了毒液蛋白，Kazal型丝氨酸蛋白酶抑制剂，蛹外寄生虫Pachycrepoideus vindemiae（PvKazal）。序列分析表明，PvKazal由一个信号肽和一个高度保守的“Kazal”结构域包装。定量聚合酶链反应分析记录了较高的转录水平的PvKazal在毒液器官相对于尸体，和PvKazal信使RNA水平出现达到高峰，在第5天postestescion。重组PvKazal对宿主果蝇血淋巴黑化有较强的抑制作用。此外，PvKazal在转基因果蝇中的异源表达减少了宿主蛹血淋巴的晶体细胞数量，并阻断了宿主蛹血淋巴的黑化。我们目前的工作PvKazal的作用的基础无疑增加了毒液介导的主机寄生虫串扰的理解。
Parasitic wasps inject various virulence factors into the host insects while laying eggs, among which the venom proteins, one of the key players in host insect/parasitoid relationships, act in host cellular and humoral immune regulation to ensure successful development of wasp progeny. Although the investigations into actions of venom proteins are relatively ample in larval parasitoids, their regulatory mechanisms have not been thoroughly understood in pupal parasitoids. Here, we identified a venom protein, Kazal-type serine protease inhibitor, in the pupal ectoparasitoid Pachycrepoideus vindemiae (PvKazal). Sequence analysis revealed that PvKazal is packed by a signal peptide and a highly conserved "Kazal" domain. Quantitative polymerase chain reaction analysis recorded a higher transcript level of PvKazal in the venom apparatus relative to that in the carcass, and the PvKazal messenger RNA level appeared to reach a peak on day 5 posteclosion. Recombinant PvKazal strongly inhibited the hemolymph melanization of host Drosophila melanogaster. Additionally, the heterologous expression of PvKazal in transgenic Drosophila reduced the crystal cell numbers and blocked the melanization of host pupal hemolymph. Our present work underlying the roles of PvKazal undoubtedly increases the understanding of venom-mediated host-parasitoid crosstalk.