Grouper Rab1 inhibits nodovirus infection by affecting virus entry and host immune response.
Grouper Rab1 inhibits nodovirus infection by affecting virus entry and host immune response.
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DOI：
10.1016/j.fsi.2023.109136
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发表时间：
2023-10
影响因子：
4.7
通讯作者：
Lingfeng Guan;Xiao-wei Wen;Zihan Zhang;Liqun Wang;Xinyue Zhang;Min Yang;Shaowen Wang;Qiwei Qin-Qi
中科院分区：
文献类型：
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作者：
Lingfeng Guan;Xiao-wei Wen;Zihan Zhang;Liqun Wang;Xinyue Zhang;Min Yang;Shaowen Wang;Qiwei Qin-Qi
Rab1是一种GTPase，存在于所有真核生物中，主要参与内质网和高尔基体之间的囊泡运输，从而调节许多细胞活动和致病性感染。然而，Rab1在病毒感染期间如何在鱼体内发挥作用尚不清楚。石斑鱼（Epinephelus spp.）具有很高的经济价值，在中国和东南亚广泛种植，尽管它们经常遭受疾病。红斑石斑鱼神经坏死病毒（RGNNV）是一种高致病性RNA病毒，是养殖石斑鱼的主要病原体，造成巨大的经济损失。鉴定了一系列参与RGNNV感染的宿主细胞蛋白。然而，Rab1对RGNNV感染的影响尚未见报道。本研究从石斑鱼（Epinephelus coioides）中克隆了一种新的Rab1同源物（EcRab1），并研究了其在病毒感染和宿主免疫应答中的作用。EcRab1编码202个氨基酸的多肽，分别与石斑猿和智人具有98%和78%的同源性。在RGNNV或poly（I:C）攻击后，EcRab1在体外和体内的转录都发生了改变，这表明EcRab1参与了病毒感染。亚细胞定位表明，EcRab1在细胞质中以点状结构显示，受EcRab1突变体的影响。显性阴性（DN） EcRab1使EcRab1保持在gdp结合状态，导致EcRab1在细胞质中弥漫性分布。组成活性（CA） EcRab1，使EcRab1保持在gtp结合状态，诱导更大的EcRab1簇结构。在RGNNV感染后期，部分EcRab1与RGNNV共定位，EcRab1簇的大小增大。重要的是，过表达EcRab1可显著抑制RGNNV感染，而敲低EcRab1可促进RGNNV感染。此外，EcRab1抑制RGNNV进入宿主细胞。与EcRab1相比，DN EcRab1或CA EcRab1的过表达也促进了RGNNV感染，这表明EcRab1调节RGNNV感染取决于GTP-和gdp结合状态的周期。此外，EcRab1正调控干扰素（IFN）免疫和炎症反应。综上所述，这些结果表明EcRab1可能通过调节宿主免疫来影响RGNNV感染。我们的研究进一步了解Rab1在病毒感染过程中的功能，从而有助于设计新的抗病毒策略。
Rab1, a GTPase, is present in all eukaryotes, and is mainly involved in vesicle trafficking between the endoplasmic reticulum and Golgi, thereby regulating many cellular activities and pathogenic infections. However, little is known of how Rab1 functions in fish during virus infection. Groupers (Epinephelus spp.) are high in economic value and widely cultivated in China and Southeast Asia, although they often suffer from diseases. Red-spotted grouper nervous necrosis virus (RGNNV), a highly pathogenic RNA virus, is a major pathogen in cultured groupers, and causes huge economic losses. A series of host cellular proteins involved in RGNNV infection was identified. However, the impact of Rab1 on RGNNV infection has not yet been reported. In this study, a novel Rab1 homolog (EcRab1) from Epinephelus coioides was cloned, and its roles during virus infection and host immune responses were investigated. EcRab1 encoded a 202 amino acid polypeptide, showing 98% and 78% identity to Epinepheluslanceolatusand Homo sapiens, respectively. After challenge with RGNNV or poly(I:C), the transcription of EcRab1 was altered bothin vitroandin vivo, implying that EcRab1 was involved in virus infection. Subcellular localization showed that EcRab1 was displayed as punctate structures in the cytoplasm, which was affected by EcRab1 mutants. The dominant negative (DN) EcRab1, enabling EcRab1 to remain in the GDP-binding state, caused EcRab1 to be diffusely distributed in the cytoplasm. Constitutively active (CA) EcRab1, enabling EcRab1 to remain in the GTP-binding state, induced larger cluster structures of EcRab1. During the late stage of RGNNV infection, some EcRab1 co-localized with RGNNV, and the size of EcRab1 clusters was enlarged. Importantly, overexpression of EcRab1 significantly inhibited RGNNV infection, and knockdown of EcRab1 promoted RGNNV infection. Furthermore, EcRab1 inhibited the entry of RGNNV to host cells. Compared with EcRab1, overexpression of DN EcRab1 or CA EcRab1 also promoted RGNNV infection, suggesting that EcRab1 regulated RGNNV infection, depending on the cycles of GTP- and GDP-binding states. In addition, EcRab1 positively regulated interferon (IFN) immune and inflammatory responses. Taken together, these results suggest that EcRab1 affects RGNNV infection, possibly by regulating host immunity. Our study furthers the understanding of Rab1 function during virus infection, thus helping to design new antiviral strategies.