Potato Mop-Top Virus Co-Opts the Stress Sensor HIPP26 for Long-Distance Movement

作者：Graham H. Cowan, Alison G. Roberts, Susan R. Jones, Pankaj Kumar, Pruthvi B. Kalyandurg, J. Gil, Eugene I. Savenkov, Piers A. Hemsley, L. Torrance · 发表于：PLANT PHYSIOLOGY · 年份：2018 · DOI：10.1104/pp.17.01698 · 被引用次数：82 · 研究领域：Plant Virus Research Studies、Plant-Microbe Interactions and Immunity、Transgenic Plants and Applications

Virus movement proteins facilitate virus entry into the vascular system to initiate systemic infection. The potato mop-top virus (PMTV) movement protein, TGB1, is involved in long-distance movement of both viral ribonucleoprotein complexes and virions. Here, our analysis of TGB1 interactions with host Nicotiana benthamiana proteins revealed an interaction with a member of the heavy metal-associated isoprenylated plant protein family, HIPP26, which acts as a plasma membrane-to-nucleus signal during abiotic stress. We found that knockdown of NbHIPP26 expression inhibited virus long-distance movement but did not affect cell-to-cell movement. Drought and PMTV infection up-regulated NbHIPP26 gene expression, and PMTV infection protected plants from drought. In addition, NbHIPP26 promoter-reporter fusions revealed vascular tissue-specific expression. Mutational and biochemical analyses indicated that NbHIPP26 subcellular localization at the plasma membrane and plasmodesmata was mediated by lipidation (S-acylation and prenylation), as nonlipidated NbHIPP26 was predominantly in the nucleus. Notably, coexpression of NbHIPP26 with TGB1 resulted in a similar nuclear accumulation of NbHIPP26. TGB1 interacted with the carboxyl-terminal CVVM (prenyl) domain of NbHIPP26, and bimolecular fluorescence complementation revealed that the TGB1-HIPP26 complex localized to microtubules and accumulated in the nucleolus, with little signal at the plasma membrane or plasmodesmata. These data support a...