Ma Xiaoyan, Li Jiang, Wang Manli, Hu Zhihong, Zhang Huanyu
State Key Laboratory of Virologyand Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
Viruses. 2025 Mar 18;17(3):434. doi: 10.3390/v17030434.
The open reading frame 103 () of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is one of the 38 core baculovirus genes. has been shown to be essential for the production of infectious budded virions (BVs), nuclear egress of nucleocapsids, envelopment of the nucleocapsid, and embedding of occlusion-derived virions (ODVs) into occlusion bodies (OBs). However, the structure-function relationship of P48 remains unclear. In this study, we showed that four conserved cysteines (C127, C130, C138, and C141) in P48 may form a zinc finger motif based on a predicted structure analysis, and we investigated the roles of these cysteines in P48 function. AcMNPV bacmids lacking or containing mutated were generated. Transfection/infection assays showed that C127, C130, C138, and C141 in P48 were crucial for infectious BV production. Electron microscopy analysis further confirmed that these four cysteines played critical roles in the transport of nucleocapsids out of the nucleus for BV production, and in ODV envelopment. These results demonstrate that the conserved cysteines C127, C130, C138, and C141, related to the putative zinc finger motif, are critical for P48 function in baculovirus infection.
苜蓿银纹夜蛾多粒包埋核型多角体病毒（AcMNPV）的开放阅读框103（P48）是38个核心杆状病毒基因之一。已证明P48对于感染性出芽病毒粒子（BVs）的产生、核衣壳的核输出、核衣壳的包被以及将多角体衍生病毒粒子（ODVs）嵌入多角体（OBs）至关重要。然而，P48的结构-功能关系仍不清楚。在本研究中，基于预测的结构分析，我们表明P48中的四个保守半胱氨酸（C127、C130、C138和C141）可能形成一个锌指基序，并且我们研究了这些半胱氨酸在P48功能中的作用。构建了缺失P48或含有突变P48的AcMNPV杆粒。转染/感染试验表明，P48中的C127、C130、C138和C141对于感染性BV的产生至关重要。电子显微镜分析进一步证实，这四个半胱氨酸在核衣壳从细胞核输出以产生BV以及ODV包被过程中起关键作用。这些结果表明，与假定的锌指基序相关的保守半胱氨酸C127、C130、C138和C141对于杆状病毒感染中P48的功能至关重要。
