Abstract

Potato virus Y (PVY) is one of the most common and harmful plant viruses. Translation of viral RNA starts with the interaction between the plant cap-binding translation initiation factors eIF4E and viral genome-linked protein (VPg) covalently attached to the viral RNA. Disruption of this interaction is one of the natural mechanisms of plant resistance to PVY. The multigene eIF4E family in the potato (Solanum tuberosum L.) genome contains genes for the translation initiation factors eIF4E1, eIF4E2, and eIF(iso)4E. However, which of these factors can be recruited by the PVY, as well as the mechanism of this interaction, remain obscure. Here, we showed that the most common VPg variant from the PVY strain NTN interacts with eIF4E1 and eIF4E2, but not with eIF(iso)4E. Based on the VPg, eIF4E1, and eIF4E2 models and data on the natural polymorphism of VPg amino acid sequence, we suggested that the key role in the recognition of potato cap-binding factors belongs to the R104 residue of VPg. To verify this hypothesis, we created VPg mutants with substitutions at position 104 and examined their ability to interact with potato eIF4E factors. The obtained data were used to build the theoretical model of the VPg-eIF4E2 complex that differs significantly from the earlier models of VPg complexes with eIF4E proteins, but is in a good agreement with the current biochemical data.

中文翻译：

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马铃薯病毒 Y 的 VPg 和马铃薯帽结合 eIF4E 因子：选择性相互作用及其假设机制

摘要

马铃薯 Y 病毒 (PVY) 是最常见和最有害的植物病毒之一。病毒 RNA 的翻译始于植物帽结合翻译起始因子 eIF4E 和病毒基因组连接蛋白 (VPg) 之间的相互作用，该蛋白共价连接到病毒 RNA。破坏这种相互作用是植物对 PVY 抗性的自然机制之一。马铃薯 ( Solanum tuberosum) 中的多基因 eIF4E 家族L.) 基因组包含翻译起始因子 eIF4E1、eIF4E2 和 eIF(iso)4E 的基因。然而，PVY 可以招募这些因素中的哪些，以及这种相互作用的机制，仍然不清楚。在这里，我们展示了 PVY 菌株 NTN 中最常见的 VPg 变体与 eIF4E1 和 eIF4E2 相互作用，但不与 eIF(iso)4E 相互作用。基于 VPg、eIF4E1 和 eIF4E2 模型和 VPg 氨基酸序列天然多态性的数据，我们认为识别马铃薯帽结合因子的关键作用属于 VPg 的 R104 残基。为了验证这一假设，我们在位置 104 处创建了具有替换的 VPg 突变体，并检查了它们与马铃薯 eIF4E 因子相互作用的能力。