The p23 of Citrus Tristeza Virus Interacts with Host FKBP-Type Peptidyl-Prolylcis-Trans Isomerase 17-2 and Is Involved in the Intracellular Movement of the Viral Coat Protein

Citrus tristeza virus is a member of the genus Closterovirus in the family Closteroviridae. The p23 of citrus tristeza virus (CTV) is a multifunctional protein and RNA silencing suppressor. In this study, we identified a p23 interacting partner, FK506-binding protein (FKBP) 17-2, from Citrus aurantifolia (CaFKBP17-2), a susceptible host, and Nicotiana benthamiana (NbFKBP17-2), an experimental host for CTV. The interaction of p23 with CaFKBP17-2 and NbFKBP17-2 were individually confirmed by yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays. Subcellular localization tests showed that the viral p23 translocated FKBP17-2 from chloroplasts to the plasmodesmata of epidermal cells of N. benthamiana leaves. The knocked-down expression level of NbFKBP17-2 mRNA resulted in a decreased CTV titer in N. benthamiana plants. Further, BiFC and Y2H assays showed that NbFKBP17-2 also interacted with the coat protein (CP) of CTV, and the complexes of CP/NbFKBP17-2 rapidly moved in the cytoplasm. Moreover, p23 guided the CP/NbFKBP17-2 complexes to move along the cell wall. To the best of our knowledge, this is the first report of viral proteins interacting with FKBP17-2 encoded by plants. Our results provide insights for further revealing the mechanism of the CTV CP protein movement.

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Comparison of the Coat Protein Gene Sequences of Citrus Tristeza Virus Isolatesin New Zealand

International Organization of Citrus Virologists Conference Proceedings (1957-2010) ◽

10.5070/c50z51r3jp ◽

2000 ◽

Vol 14 (14) ◽

Author(s):

P. A. Mooney ◽

T. E. Dawson ◽

C. L. Niblett

Keyword(s):

New Zealand ◽

Coat Protein ◽

Coat Protein Gene ◽

Citrus Tristeza Virus ◽

Protein Gene ◽

Gene Sequences ◽

Tristeza Virus ◽

Citrus Tristeza

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Production of polyclonal antibodies against the recombinant citrus tristeza virus coat protein expressed in bacteria

International Journal of Virology ◽

10.3923/ijv.2005.7.7 ◽

2004 ◽

Vol 1 (1) ◽

pp. 7-7

Author(s):

Hala A. Amin . ◽

A. Barakat . ◽

A.A. Abou Zeid .

Keyword(s):

Coat Protein ◽

Citrus Tristeza Virus ◽

Polyclonal Antibodies ◽

Virus Coat Protein ◽

Virus Coat ◽

Tristeza Virus ◽

Citrus Tristeza

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A Non-Conserved p33 Protein of Citrus Tristeza Virus Interacts with Multiple Viral Partners

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-11-19-0328-fi ◽

2020 ◽

Vol 33 (6) ◽

pp. 859-870 ◽

Cited By ~ 2

Author(s):

Thi Nguyet Minh Dao ◽

Sung-Hwan Kang ◽

Aurélie Bak ◽

Svetlana Y. Folimonova

Keyword(s):

Host Range ◽

Citrus Tristeza Virus ◽

Protein A ◽

Integral Membrane Protein ◽

Open Reading Frames ◽

Bimolecular Fluorescence Complementation ◽

In Planta ◽

Tristeza Virus ◽

Citrus Tristeza

The RNA genome of citrus tristeza virus (CTV), one of the most damaging viral pathogens of citrus, contains 12 open reading frames resulting in production of at least 19 proteins. Previous studies on the intraviral interactome of CTV revealed self-interaction of the viral RNA-dependent RNA polymerase, the major coat protein (CP), p20, p23, and p33 proteins, while heterologous interactions between the CTV proteins have not been characterized. In this work, we examined interactions between the p33 protein, a nonconserved protein of CTV, which performs multiple functions in the virus infection cycle and is needed for virus ability to infect the extended host range, with other CTV proteins shown to mediate virus interactions with its plant hosts. Using yeast two-hybrid, bimolecular fluorescence complementation, and coimmunoprecipitation assays, we demonstrated that p33 interacts with three viral proteins, i.e., CP, p20, and p23, in vivo and in planta. Coexpression of p33, which is an integral membrane protein, resulted in a shift in the localization of the p20 and p23 proteins toward the subcellular crude-membrane fraction. Upon CTV infection, the four proteins colocalized in the CTV replication factories. In addition, three of them, CP, p20, and p23, were found in the p33-formed membranous structures. Using bioinformatic analyses and mutagenesis, we found that the N-terminus of p33 is involved in the interactions with all three protein partners. A potential role of these interactions in virus ability to infect the extended host range is discussed.

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