Tombusviruses Target a Major Crossroad in the Endocytic and Recycling Pathways via Co-opting Rab7 Small GTPase
Tombusviruses Target a Major Crossroad in the Endocytic and Recycling Pathways via Co-opting Rab7 Small GTPase
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DOI：
10.1128/jvi.01076-21
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发表时间：
2021-11-01
影响因子：
5.4
通讯作者：
Nagy, Peter D.
中科院分区：
文献类型：
--
作者：
Feng, Zhike;Inaba, Jun-ichi;Nagy, Peter D.
正链RNA病毒诱导称为病毒复制细胞器（VRO）的独特膜细胞器的生物发生，其在感染的细胞中进行病毒复制。Tombusviruses已被证明可以重新连接细胞运输和代谢途径，重塑宿主膜，并招募多种宿主因子来支持病毒复制。在这项工作中，我们证明，番茄丛矮病毒（TBSV）和密切相关的康乃馨意大利环斑病毒（CIRV）篡夺Rab 7小GTbirth，以促进建设VRO在替代宿主酵母和植物。晚期内体和逆转录酶体生物发生所需的Rab 7小GT3的耗尽强烈抑制TBSV和CIRV在酵母和植物中的复制。病毒p33复制蛋白与Rab 7小GT酶相互作用，导致Rab 7重新定位到大VRO中。与Rab 7的缺失类似，Rab 7的MON 1或CCZ 1异二聚体GEF（鸟嘌呤核苷酸交换因子）的缺失抑制TBSV RNA在酵母中的复制。这表明激活的Rab 7具有前病毒功能。我们发现Rab 7的前病毒功能是促进retromer复合物和内体分选连接蛋白-BAR蛋白进入VRO的募集。我们证明了TBSV p33驱动的Rab 7重定向到VRO中导致几种具有前病毒功能的逆转录病毒货物的递送。这些蛋白质包括脂质酶，例如Vps 34 PI 3 K（磷脂酰肌醇3-激酶）、PI 4K α-样Stt 4磷脂酰肌醇4-激酶和Psd 2磷脂酰丝氨酸脱羧酶。总之，基于这些和以前的研究结果，我们建议，颠覆Rab 7到VRO允许tombusviruses重新路由内吞和回收贩运，以支持病毒replication.IMPORTANCE复制的正链RNA病毒依赖于病毒复制细胞器（VRO）的生物合成。然而，膜VRO的形成还没有得到很好的理解。使用tombusviruses和模式宿主酵母，我们发现，内体Rab 7小GT3对VRO的形成至关重要。Rab 7和TBSV p33复制蛋白之间的相互作用导致Rab 7募集到VRO中。TBSV驱动的Rab 7的篡夺具有前病毒功能，通过促进共选择的逆转录复合物的递送、将连接蛋白-BAR蛋白和脂质酶分选到VRO中以创建用于病毒复制的最佳环境。这些结果开辟了控制感染细胞中细胞Rab 7活性可能成为新的抗病毒策略的目标的可能性。
Positive-strand RNA viruses induce the biogenesis of unique membranous organelles called viral replication organelles (VROs), which perform virus replication in infected cells. Tombusviruses have been shown to rewire cellular trafficking and metabolic pathways, remodel host membranes, and recruit multiple host factors to support viral replication. In this work, we demonstrate that tomato bushy stunt virus (TBSV) and the closely related carnation Italian ringspot virus (CIRV) usurp Rab7 small GTPase to facilitate building VROs in the surrogate host yeast and in plants. Depletion of Rab7 small GTPase, which is needed for late endosome and retromer biogenesis, strongly inhibits TBSV and CIRV replication in yeast and in planta. The viral p33 replication protein interacts with Rab7 small GTPase, which results in the relocalization of Rab7 into the large VROs. Similar to the depletion of Rab7, the deletion of either MON1 or CCZ1 heterodimeric GEFs (guanine nucleotide exchange factors) of Rab7 inhibited TBSV RNA replication in yeast. This suggests that the activated Rab7 has proviral functions. We show that the proviral function of Rab7 is to facilitate the recruitment of the retromer complex and the endosomal sorting nexin-BAR proteins into VROs. We demonstrate that TBSV p33-driven retargeting of Rab7 into VROs results in the delivery of several retromer cargos with proviral functions. These proteins include lipid enzymes, such as Vps34 PI3K (phosphatidylinositol 3-kinase), PI4K alpha-like Stt4 phosphatidylinositol 4-kinase, and Psd2 phosphatidylserine decarboxylase. In summary, based on these and previous findings, we propose that subversion of Rab7 into VROs allows tombusviruses to reroute endocytic and recycling trafficking to support virus replication.IMPORTANCE The replication of positive-strand RNA viruses depends on the biogenesis of viral replication organelles (VROs). However, the formation of membranous VROs is not well understood yet. Using tombusviruses and the model host yeast, we discovered that the endosomal Rab7 small GTPase is critical for the formation of VROs. Interaction between Rab7 and the TBSV p33 replication protein leads to the recruitment of Rab7 into VROs. TBSV-driven usurping of Rab7 has proviral functions through facilitating the delivery of the co-opted retromer complex, sorting nexin-BAR proteins, and lipid enzymes into VROs to create an optimal milieu for virus replication. These results open up the possibility that controlling cellular Rab7 activities in infected cells could be a target for new antiviral strategies.