Nucleocapsid of Tomato spotted wilt tospovirus forms mobile particles that traffic on an actin/endoplasmic reticulum network driven by myosin XI-K

Authors

  • Zhike Feng,

    1. Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
    Search for more papers by this author
  • Xiaojiao Chen,

    1. Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
    Search for more papers by this author
  • Yiqun Bao,

    1. College of Life Sciences, Nanjing Agricultural University, Nanjing, China
    Search for more papers by this author
  • Jiahong Dong,

    1. Yunnan Provincial Key Laboratory of Agri-Biotechnology, Institute of Biotechnology and Genetic Resources, Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, China
    Search for more papers by this author
  • Zhongkai Zhang,

    1. Yunnan Provincial Key Laboratory of Agri-Biotechnology, Institute of Biotechnology and Genetic Resources, Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, China
    Search for more papers by this author
  • Xiaorong Tao

    Corresponding author
    1. Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
    Search for more papers by this author

Summary

  • A number of viral proteins from plant viruses, other than movement proteins, have been shown to traffic intracellularly along actin filaments and to be involved in viral infection. However, there has been no report that a viral capsid protein may traffic within a cell by utilizing the actin/endoplasmic reticulum (ER) network.
  • We used Tomato spotted wilt tospovirus (TSWV) as a model virus to study the cell biological properties of a nucleocapsid (N) protein.
  • We found that TSWV N protein was capable of forming highly motile cytoplasmic inclusions that moved along the ER and actin network. The disruption of actin filaments by latrunculin B, an actin-depolymerizing agent, almost stopped the intracellular movement of N inclusions, whereas treatment with a microtubule-depolymerizing reagent, oryzalin, did not. The over-expression of a myosin XI-K tail, functioning in a dominant-negative manner, completely halted the movement of N inclusions. Latrunculin B treatment strongly inhibited the formation of TSWV local lesions in Nicotiana tabacum cv Samsun NN and delayed systemic infection in N. benthamiana.
  • Collectively, our findings provide the first evidence that the capsid protein of a plant virus has the novel property of intracellular trafficking. The findings add capsid protein as a new class of viral protein that traffics on the actin/ER system.

Ancillary