Department of Agricultural Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland.
Mol Plant Microbe Interact. 2013 Jul;26(7):734-44. doi: 10.1094/MPMI-01-13-0023-R.
Microtubules (MT) outline and maintain the overall shape of cells and can reorganize cellular membranes to serve as sites of RNA virus replication. Here, we provide data on involvement of an MT-associated protein in infection of plants with a potyvirus, Potato virus A (PVA), representing the largest family of plant-infecting RNA viruses. Our results showed that helper-component proteinase (HCpro)-interacting protein 2 (HIP2) of potato (Solanum tuberosum) is an MT-associated protein similar to Arabidopsis SPR2. Virus-induced silencing of HIP2 in Nicotiana benthamiana resulted in a spiral-like growth phenotype, similar to the Arabidopsis spr2 mutant, and the spr2 phenotype in Arabidopsis was complemented with potato HIP2. HCpro of PVA interacted with HIP2 of potato and tobacco (Nicotiana tabacum). The interaction was detected by bimolecular fluorescence complementation in PVA-infected leaves on MT and MT intersections at the cell cortex. HIP2-HCpro interaction was determined by the C-proximal α-helix-rich domain of HIP2, whereas the N-proximal putative TOG domain and the central coiled-coil domain of HIP2 controlled HIP2 dimerization and binding to MT. Accumulation of PVA was significantly reduced in the HIP2-silenced leaves of N. benthamiana, which indicates that HIP2-HCpro interactions are important for virus infection.
微管（MT）勾勒并维持细胞的整体形状，并可重新组织细胞膜，作为 RNA 病毒复制的场所。在这里，我们提供了与 MT 相关的蛋白质参与感染马铃薯病毒 A（PVA）的植物的数据，PVA 代表了最大的植物感染 RNA 病毒家族。我们的结果表明，马铃薯（Solanum tuberosum）的辅助成分蛋白酶（HCpro）相互作用蛋白 2（HIP2）是一种与拟南芥 SPR2 相似的 MT 相关蛋白。在本氏烟中沉默 HIP2 会导致螺旋状生长表型，类似于拟南芥 spr2 突变体，并且拟南芥中的 spr2 表型可以用马铃薯 HIP2 互补。PVA 的 HCpro 与马铃薯和烟草（Nicotiana tabacum）的 HIP2 相互作用。在 PVA 感染的叶片上，通过双分子荧光互补，在细胞皮层的 MT 和 MT 交叉处检测到了这种相互作用。HIP2-HCpro 相互作用由 HIP2 的 C-近端富含α-螺旋的结构域决定，而 HIP2 的 N-近端假定的 TOG 结构域和中心卷曲螺旋结构域控制 HIP2 的二聚化和与 MT 的结合。在本氏烟的 HIP2 沉默叶片中，PVA 的积累显著减少，这表明 HIP2-HCpro 相互作用对病毒感染很重要。
