Yang Lei, Qiu Liming, Fang Qi, Wu Shaoying, Ye Gongyin
Hainan University, Haikou, 570228, China.
State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, 310058, China.
Insect Sci. 2022 Apr;29(2):399-410. doi: 10.1111/1744-7917.12935. Epub 2021 Nov 1.
To achieve successful development, female parasitoids, while laying eggs, introduce various virulence factors, mainly venoms, into host insects to manipulate their physiology. Although numerous studies have been conducted to characterize the components of venoms that regulate host immune responses, few systematic investigations have been conducted on the roles of venom proteins in host metabolic regulation. In this investigation, we characterized a novel venom protein in Pachycrepoideus vindemiae called glucose-6-phosphate dehydrogenase (PvG6PDH) and showed it has a vital role in regulating host carbohydrate metabolism. PvG6PDH encodes 510 amino acids and features a signal peptide and two conserved "G6PDH" domains. Multiple sequence alignment showed it has high amino acid identity with G6PDH from other pteromalids, and quantitative polymerase chain reaction analysis and immunofluorescent staining demonstrated a significantly higher expression of PvG6PDH in the venom apparatus compared with the carcass. We report that PvG6PDH contributes to parasitism by inhibiting the glucose-6-phosphate (G6P) metabolism of host Drosophila melanogaster, as demonstrated by PvG6PDH injection and RNA interference analysis. Further tests revealed that the accumulation of host G6P was caused by the transcriptional inhibition of G6P-metabolism-related genes. These findings greatly contribute to our understanding of venom-mediated host metabolic regulation, further laying the foundation for the development of venom proteins as biological agents for pest control.
为实现成功发育，雌性寄生蜂在产卵时会将多种毒力因子（主要是毒液）注入宿主昆虫体内，以操纵其生理机能。尽管已经开展了大量研究来表征调节宿主免疫反应的毒液成分，但关于毒液蛋白在宿主代谢调节中的作用，却鲜有系统的研究。在本研究中，我们鉴定了一种在温氏厚结茧蜂中名为葡萄糖-6-磷酸脱氢酶（PvG6PDH）的新型毒液蛋白，并表明它在调节宿主碳水化合物代谢中起着至关重要的作用。PvG6PDH编码510个氨基酸，具有一个信号肽和两个保守的“G6PDH”结构域。多序列比对显示，它与其他姬小蜂科昆虫的G6PDH具有较高的氨基酸同一性，定量聚合酶链反应分析和免疫荧光染色表明，与虫体相比，PvG6PDH在毒腺中的表达显著更高。我们报告称，PvG6PDH通过抑制宿主黑腹果蝇的葡萄糖-6-磷酸（G6P）代谢来促进寄生，PvG6PDH注射和RNA干扰分析证明了这一点。进一步的测试表明，宿主G6P的积累是由G6P代谢相关基因的转录抑制引起的。这些发现极大地有助于我们理解毒液介导的宿主代谢调节，进一步为将毒液蛋白开发为害虫防治生物制剂奠定基础。
