Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, 37996, USA.
International Research Center for Agricultural & Environmental Biology, Kumamoto University, Kumamoto, 860-8555, Japan.
Arch Virol. 2024 Jun 12;169(7):143. doi: 10.1007/s00705-024-06071-x.
Potyvirus genomes are expressed as polyproteins that are autocatalytically cleaved to produce 10 to 12 multifunctional proteins, among which P1 is the most variable. It has long been hypothesized that P1 plays role(s) in host adaptation and host specificity. We tested this hypothesis using two phylogenetically distinct potyviruses: soybean mosaic virus (SMV), with a narrow host range, and clover yellow vein virus (ClYVV), with a broader host range. When the full-length P1 cistron of SMV-N was replaced with P1 from ClYVV-No.30, the chimera systemically infected only SMV-N-permissive hosts. Hence, there were no changes in the host range or host specificity of the chimeric viruses. Despite sharing only 20.3% amino acid sequence identity, predicted molecular models of P1 proteins from SMV-N and ClYVV-No.30 showed analogous topologies. These observations suggest that P1 of ClYVV-No.30 can functionally replace P1 of SMV-N. However, the P1 proteins of these two potyviruses are not determinants of host specificity and host range.
马铃薯 Y 病毒属基因组以多聚蛋白的形式表达，该多聚蛋白能自我催化裂解产生 10 到 12 种多功能蛋白，其中 P1 是变化最大的。人们长期以来一直假设 P1 在宿主适应和宿主特异性方面发挥作用。我们使用两种系统发育上不同的马铃薯 Y 病毒属病毒来检验这一假说：大豆花叶病毒（SMV），宿主范围较窄；三叶草黄脉病毒（ClYVV），宿主范围较宽。当 SMV-N 的全长 P1 顺式元件被 ClYVV-No.30 的 P1 取代时，嵌合体只能系统感染允许 SMV-N 感染的宿主。因此，嵌合病毒的宿主范围或宿主特异性没有变化。尽管 SMV-N 和 ClYVV-No.30 的 P1 蛋白仅共享 20.3%的氨基酸序列同一性，但预测的分子模型显示它们具有类似的拓扑结构。这些观察结果表明，ClYVV-No.30 的 P1 可以在功能上替代 SMV-N 的 P1。然而，这两种马铃薯 Y 病毒属病毒的 P1 蛋白不是宿主特异性和宿主范围的决定因素。
