丝氨酸蛋白酶抑制剂 4 通过抑制亚洲玉米螟（Guenée）黑化促进杆状病毒感染
Serpin-4 Facilitates Baculovirus Infection by Inhibiting Melanization in Asian Corn Borer, (Guenée).
机构信息
Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, China.
Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.
出版信息
Front Immunol. 2022 Jun 9;13:905357. doi: 10.3389/fimmu.2022.905357. eCollection 2022.
Phenoloxidase (PO)-catalyzed melanization is a vital immune response in insects for defense against pathogen infection. This process is mediated by clip domain serine proteases and regulated by members of the serpin superfamily. We here revealed that the infection of multicapsid nucleopolyhedrovirus (AcMNPV) significantly inhibited the PO activity in hemolymph and induced the expression of . Addition of recombinant serpin-4 protein to hemolymph resulted in a great increase of AcMNPV copies. Serpin-4 significantly suppressed the PO activity and the amidase activity in cleaving colorimetric substrate IEARNA (IEARase activity) of hemolymph. Further experiments indicated it formed covalent complexes with three serine proteases (SP1, SP13 and SP105) and prevented them from cleaving their cognate downstream proteases . Altogether, melanization restricted AcMNPV replication and serpin-4 facilitated AcMNPV infection by inhibiting serine proteases, SP1, SP13, and SP105 which were all involved in the melanization response.
酚氧化酶（PO）催化的黑化是昆虫抵御病原体感染的重要免疫反应。该过程由 clip 结构域丝氨酸蛋白酶介导，并受丝氨酸蛋白酶抑制剂超家族成员的调节。我们在此揭示，多角体核型多角体病毒（AcMNPV）的感染显著抑制了血淋巴中的 PO 活性，并诱导了 的表达。将重组丝氨酸蛋白酶抑制剂-4 蛋白添加到血淋巴中会导致 AcMNPV 拷贝数的大量增加。丝氨酸蛋白酶抑制剂-4 显著抑制了 PO 活性和裂解比色底物 IEARNA 的酰胺酶活性（IEARase 活性）。进一步的实验表明，它与三种丝氨酸蛋白酶（SP1、SP13 和 SP105）形成共价复合物，并阻止它们切割其同源下游蛋白酶。总之，黑化限制了 AcMNPV 的复制，而丝氨酸蛋白酶抑制剂-4 通过抑制丝氨酸蛋白酶 SP1、SP13 和 SP105 促进了 AcMNPV 的感染，这三种酶均参与了黑化反应。
Zotero 插件